I swear, out of all the videos that explain power and torque (which have many more views than this video) this one is the most clearly explained and complete. This video was really helpful. I'm glad I came across this video.
Wow! Thanks for the rundown on the physics behind torque and horsepower. I'm watching more videos about cars and how they work, but have definitely been lacking on combining this new knowledge with my limited knowledge of mechanics. Thanks for helping me begin to bridge the gap. And I loved the info on electric engines, too!
I have watched more videos explaining this subject than I care to admit, and finally, this is the video where it finally made sense. Thank you so, so, so much for this!
Superb video. But, let me share this here knowing it can uplift someone that comes across it. Effective financial management made me rich and it is all you need if you want to build a strong financial future tomorrow. I started with 1000USD, 3 years ago I invested in a diversified stock market and fast forward to now I am worth 500000USD and am currently finishing my 8 unit apartments. I'm only 35 years old. Diversified stock investments have always proven to be very profitable, especially with the help of experts.
I'm really impressed. At 35, i was worth a little over $200,000 from * in the stock market. But what you've done with your *finances* and numbers you worth, is pure genius.
*Investing* in diversified stocks is a real hustle that has made me . I have two active stock portfolios and hope to create a third, which will increase my total return on earnings to over 120000USD
You have done well. It's people like you who set the benchmark for people like us to know that achieving financial stability and transition of status from being comfortable to wealthy is possible with the right *investment* plan.
@@sarahtjoanne5300 Experience plays a key role when *investing* in diversified *stock markets*, which is why I have Rachel Hilda, whose experience has greatly helped me persevere in the diversified *stock market*. For three years she helped me grow my portfolio using her diversified knowledge of the financial *market*.
This is the video that FINALLY, I repeat _FINALLY_ taught me where engine torque actually comes from. The example of loosening a bolt with a wrench to define what torque is has been done by countless "what's torque" videos, and I understood what torque is alright, but I just couldn't transfer the concept to vehicles. My thought was "Ok, but when a car is moving, it's the other way around: you turn the wheels' center so that the wheel can rotate and the vehicle can move, you are not acting on the wheels like you'd do with the wrench". Those videos, at least the ones I've watched, missed the part at 2:35 - it all starts with the pistons being pushed by the working fluid (air-gas mixture, air-diesel mixture, steam...), and the pistons in turn push or pull their crankpins in the crankshaft, making the latter rotate. The pistons pushing the crankpins and rotating the 'shaft are like our jands pushing on the wrench to loosen (rotate) the bolt. It's then relatively easy to work your way to the wheels from this point!! Thanks for the video and the explanation!!!
It is a common misconception to believe that a longer stroke generates higher torque. The complete physics and thermodynamics of it all are quite complex, but in general terms, for a given displacement, the longer stroke is offset by the smaller piston area on which the combustion gases apply pressure, which results in less force being applied. Truck engine make more torque because they are big: there is no substitute for displacement. Also, a 300hp engine will be able to move the same heavy load up a hill at the exact same speed, be it a 8000rpm sports car engine or a big diesel truck engine, it's all in the gearing. Truck engines are "tuned for torque" simply for durability and fuel economy reasons. By being able to generate the desired power levels at low RPM, they can last way longer and consume less fuel in the process.
Great explanation. Torque is an expression of twisting force with NO REGARD FOR SPEED. It could be at 0 rpm or 10,000 rpm. Horsepower is a more complete expression of performance, taking both torque and speed into account. As is common when speaking of car engines, torque is usually noted AT a particular speed. This is in fact all we need to compute HP, but the math is simply not completed. We could just as easily say that X engine makes 360 hp at 3500 rpm (its torque peak) and 500 hp at 6250 rpm (its hp peak). Graphing this curve really tells us a lot. We can double HP by either doubling torque OR by doubling the rpm at which the same torque is produced. Or more realistically, by increasing BOTH factors to a lesser degree. Assuming proper gearing, the engine with more horsepower will ultimately do work more quickly. OTOH, most of us don't operate street cars at their HP peak very often. It is unpleasant (to police at least) and hard on the engine. Low rpm and part throttle torque is useful in everyday cars because they spend so much of their time in that range.
Horsepower at the engine is more important than torque at the engine. If you have horsepower at the engine, you can always use gearing (torque multiplication) to increase the torque. If all you have is torque, you CANNOT get extra power by modifying the gearing. Ever. That's physics.
@@dudulin1359 Because they run all day, every day and need efficiency and longevity. Not because a higher revving engine "wouldn't work." It would work fine but it would be less efficient and would not last in the application.
Got it! Quite understandable, so sounds like the engine is like a tool, no such the best in all variations but the most suitable in certain conditions tho? Meaning not always the best seeking for high HP🤔
That’s the best explanation I’ve ever come across. The Narration and the visual aid provided a great way of understanding the whole process. Thank you very much.
Power is how fast you (or the engine) generate chunks of energy and torque is sort of how big are the chunks. The piston strokes are “stronger” with more torque. That’s half of the problem. The next problem is why small chunks at high rate is equivalent to high chunks at low rate. You can try on a bicycle, to go on a slope you can either use lower gear and low torque or high gear and push hard with the bicycle going the same speed in both cases. So with high torque you will use a high gear ratio. But what about high torque and low gear ratio. That can be done and the rpm will go up quickly so you will need to be capable of high rpm but high rpm and high torque simply means a lot more power so in that case you have a more powerful engine. Another problem is trying to analyze the power curve. You can have high torque from low rpm. That also means high power not only torque at that low rpm and that makes the car relatively fast without needing to push the rpm high.
About the 'chunks of energy' verbiage; what you are saying seems consistent and clear, but it points to a common misunderstanding of power if I'm interpreting your meaning correctly. I sincerely want to help more people actually understand power. There are so many people who will have good ideas in vehicular engineering, and have drive to make stuff happen, but have a common and crippling misunderstanding of power. It's a really foundational thing to understand and unlocks a lot of doors. You seem to be describing power as though it is equivalent to engine speed, as the rate of producing chunks of energy REGARDLESS of their size. In truth, power is the rate of producing chunks of energy INCLUSIVE of their size. Engine torque is "swallowed up" in the significance of power. It is (in one of it's many forms) simply rotational speed times torque. In your examples, you speak of power and torque as two different ways to achieve a particular level of performance. This is largely true for RPM and torque, but NOT true for power and torque in any way, ever. Because power is the product of torque and something dimensionally different (engine speed), power and torque are dimensionally incomparable. (Tangent: 5252 rpm has no physical significance at all) To know the actual thrust force that an engine is imparting to any wheel-driven vehicle at some moment while it is moving, all we need to know is the engine's power at that moment. We know a little of that power is lost in the transmission / final drive / tires, but besides these, thrust depends only on power and vehicle speed at that moment. If we don't know the engine power, then even if we know the torque the engine is producing at that moment, we can only guess at thrust it's providing, because we must NOT know the mechanical advantage (gearing and wheel diameter) that connect that engine to the road - basically the ratio of distance rolled per engine revolution). If we did, then we do know power, because that ratio together with the vehicle speed dictates the engine speed. All this assumes that the tires and clutch aren't slipping, but that's really the only significant assumption. Is this making sense?
Great video! Do you still have a link to the outro music? I think the original is gone. I was jamming after your awesome video and wanted to keep the vibe up
Never ceases to amaze me how many people get this wrong. Torque is measured in lb-ft not ft-lbs. Ft-lbs is a measure of energy. T=FxR, F for force in lbs and R for radius in ft... lb-ft. Sorry, I don´t want to be ´that guy´ but this issue grinds my gears, so to speak.
Incredible. Wish i could buy u a drink. Thanks. Torque and its formula is as eady as 2+2, but understanding it related to the engine gave me problems. 10 vids in, I found the answer thanks so much
It all starts with Torque. An electric motor can produce all its torque at 0 rpm. That means 0 horsepower. It’d be the same as pulling maximum force on a spanner but it doesn’t budge. All torque and no work so no power. But, the opposite can never be true.
It does not explain why the torque decreases yet the total power increases this should be explained. Engine friction increases which decreases torque with higher revs, but despite less torque the extra revolutions still give more power. Example less power per engine revolution but twice as many revolutions still give more usable power in a minute. Engine design and breathing size all alter the torque curve
I think there's a lot of confusion in the racing / sim racing world about torque vs power. For instance, many games give you a graph of torque and horsepower, and we are often told to pay more attention to torque (regarding when to shift) because that is where acceleration occurs. But I still get confused, because they say power is the ability to move a mass quickly, so doesn't that directly imply acceleration? Plus horsepower is always the first spec about a car that is bragged about. I'm also curious how overcoming friction ties into this. As a racer, I want to understand this better, but the information still conflicts in my head.
Well, yes power is what is needed to accelerate quickly. But it's more complicated than that. In order to accelerate a mass at any given rate, a force is needed. In a car's case, that force comes as the push that the tires give to the car. That comes from torque. So in order to accelerate a car quickly, a certain amount of torque is needed. In order for the car to accelerate at a constant rate, that torque is needed all the time (actually in the real world, as a car goes faster, more torque is needed to keep the acceleration rate the same). Which means the producer of that torque needs to produce that torque at an ever increasing rate. You can think of it like pushing against something really heavy to move it; as soon as what you're pushing moves, you have to move with it in order to keep pushing on it with the same force. The faster it moves, the faster you have to move. That is what power is: the rate at which a push happens. We tend to think of things like the example I just gave: humans doing work. The pushing force that different humans can generate varies widely: a huge man can push way more than a child, but the different rates we can push at are not all that great: we all move at close to the same rate. So we get into this stupid debate about whether torque or power is more important. Machines don't work like humans, however. With gearing, the force that machines are able to exert on objects is limited only by the strength of materials. So, it is the rate at which a force can be implemented that matters with machines. That is the definition of power. In mechanical systems, it is power that matters. Power, and gearing or force manipulation. With enough manipulating of force, any mass can be moved. The rate that it can be moved is constrained by the power input into the system. The author of this video made a couple small mistakes that might be confusing. All you have to remember is that when it comes to mechanical systems: Power is what matters. Friction is just another force on the system, same as inertia or wind resistance.
@@tylerfb1 I like your analogy of looking at a linear motion (with Push and Velocity), to intuitively imagine how an equivalent rotational motion (with Torque and RPM) works. It is now clear to me why it's not just important for a car engine to deliver Torque (push), but to be able to deliver similar levels of torque at higher RPMs (velocity) -> ignoring wind-resistance for now. However, there's sometime that's still un-intuitive to me: Preface: I understand that Engine (Crankshaft) Torque and RPM "need not be the same" as the transmission (Wheel) Torque and RPM respectively. If we can manipulate torque ("force manipulation") by using gears to any extent, does that mean that I can fit a family car's engine to a huge truck, and tune the gear-ratios in such a way, that the small engine can still move the huge load? Or will the engine simply stall, because it cannot turn the wheels of such a heavy truck? Hope you can explain this to me in an intuitive way. Rephrased question: Is it even important for a car engine to be able to offer "good" torque, if we can simply multiply the output torque on the wheels, using appropriate right gears?
@@nischalshetty2411 yes you can use a family car engine in a truck, and further more, if it has the same power as the big truck engine, it will theoretically accelerate the truck at the same rate! But there’s a big “if” there: if we can manipulate torque all we want without penalty. In the real world, we can’t do that. My comment is meant to help wrap your head around the theoretical concepts at play with power and torque. What is left out is all the other real-world implications. Engineering is about striking the balance between many, often competing, requirements. The transmission that would be required to implement a car motor in a truck would be large, heavy, and expensive: in short impractical. Efficiency, maintenance costs, and service life are very important considerations in commercial vehicles. Diesel truck motors are very efficient in their applications. They create power at low RPM, which means lower maintenance and higher service life when compared to equal gas engines and certainly a car motor used in a truck. It also means they turn more fuel energy into motion then an equivalent gasoline engine (they use less fuel for the same power output). They have lots of torque, which means they don’t need extreme gear reductions to create the needed wheel torque. Even the packaging: how much space an engine/transmission take up and how they are mounted to the vehicle is a requirement of concern. So, while it is true that power input is the only concern as far as acceleration and motion are concerned, in a practical application, there is so much more to the equation. That’s why the engines we see in use in all these different applications are the engines we use in those applications. 😊
@@nischalshetty2411 let me more directly answer your question, and give you a picture. Let’s say you had a transmission that turned the wheels one revolution for each 100,000 revolutions of the engine. Even if the engine was rigidly coupled to the transmission input, you start that engine, and rev it to 10,000 rpm for ten minutes before the wheels turn once. How much force would you have to hold those wheels with before you were able to stop the engine? If the engine makes 500 ft lbs at 10,000 rpm, it would take 50 million ft lbs to stop it. That’s the weight of 50 A380s. I hope you can see that with infinite torque manipulation, a simple family car motor could easily move a truck without stalling. 😊
no. the amount of tq at the wheel to rotate something is called tq. that doesnt change but how much tq you can apply based on how fast the car is going based on the road is called hp. the faster you are travelling, and you want to make the same wheel tq, you need more hp. this is why trucks always make lots of tq. the relationship of these two things is the whole point... a 1hp car, can infact make a "technically" infinite amount of tq, but at an infinitely slow speed... a large amount of hp can do "techinically" the same thing at an ever increasing higher speed of the vehicle. this is why the trap speed of a mass going down the 1/4 mile is based on hp, not tq. hope this helps
well of couse this matters. but it is literally changing one variable and affecting another. longer strokes means more tq per explosion, but you reduce your rpms. so one affects the others. the real problem is weight balance, harmonic balance and wha you want the motor to do...
Sure, but also long strokes means the pressure inside the cylinder can be released later. As the piston travels down the pressure drops so basically you have an initial high torque then towards the end of the travel the force of the piston drops more and the torque is reduced. Anyway on average there will be more torque but these engines will produce less power (if not using forced induction of course, in that case torque goes up a lot more). It’s basically a configuration for economy because you use extra energy left in the cylinder. With short stroke you will also be able of higher rpm. That the case for sports engines with 7-9k rpm
@@rotorblade9508 we all agree that long strokes create more tq. simply by the crank arm is longer. i really dont understand what you are arguing for or against. you seem to agree why not just thumbs up or make a counter argument.
Let me ask a question - does torque affect fuel consumption? If in my engine at 1750 rpm is the max torque (200 nm), and at 2500 it’s 150 nm, it means that driving at 1750 will consume less fuel than on 2500 rpm?
No not really. You will only get the maximum torque for any given revs, if you put your foot full on the gas. If you do that, then unless you're going up a steep hill you are going to accelerate and the revs will increase anyway . Obviously putting your foot on the gas does use more fuel, but you can maintain revs at say 1750rpm by easing off the gas and therefore lowering the torque output to just sufficient to keep going at the same speed . Generally though you will get the best fuel efficiency from most petrol engines in top gear at around 2000rpm.
@@smiler447 I’ve learnd how it works, it seems that it depends over if the engine has turbocharger. If so, keeping revs lower will give better fuel consumption, at naturally aspirated engine it’s like you’ve said
@@FaizanAli-op2xe best example is a history of chevy small block engine. Compare LT1 5.7L for Caprice with 260hp, Firebird with 275hp and Corvette with 300hp. So #1 reason is shifting torque along the rpm scale higher (for more power) or lower (for better fuel efficiency). Torque shows an efficiency of combustion cycle. ICE is an air pump that works at different speeds (750-6500rpm), and air feeding can't be optimised for such a wide range. Unless you have a VVT, VVL and variable intake geometry technology.
power (watt) = torque (Newton meter) * angular speed (radian / s = 2 * pi * rpm / 60). torque is a parameter of power. so do you need torque or power? answer both my general. the interest of the couple only appears on the acceleration aspect inertia * acceleration = motor torque - resistant torque (simplified presentation). If you want good acceleration, decrease the inertias (moving masses) and increase the engine torque, the resistive torque being fixed by the tires, aerodynamics and the slope of the road. if you want to go fast you need power to obtain equal engine torque = resistant torque at cruising speed (at high speed the aerodynamic effects are enormous) as explained, electric motors have a much more favorable torque versus speed curve than thermal motors.
When you introduce torque, force and leverage become obsolete. You got 400nm and you dont care if it comes from 3.0 diesel (leverage) or from 5.7 gasoline (force). 1kg of steel = 1kg of cotton candy. Same thing with power. When power is introduced torque becomes obsolete. Power is speed times acceleration divided by mass. There is no torque here. It is somewhere inside power and we dont care about it.
@@IgorArkin The couple is interesting when we are interested in dynamic regimes (fundamental relation of dynamics). For a rotational movement J * angular acc = Motor torque-resistant torque (with J moment of inertia in kg.m2, acc in rad / s2, Torques in Nm). So knowing only the power of an engine is not enough, you also need the torque curve to determine the acceleration capacities. The dynamic behavior will also depend on the moment of inertia of the moving parts, so the choice of materials and their shape have a significant influence on performance. So when you tell me that the torque of a diesel is the same as for a gasoline engine, it is very likely that the moving parts of the diesel are heavier than for the gasoline engine so that the inertias are greater therefore that the accelerations are less with the same torque. In position control systems, motors are dimensioned in torque rather than in power with rotor shapes reducing inertia to obtain great reactivity.
@@IgorArkin To continue the explanations, the torque curve will determine the design of the gearbox and its staging (not the same between diesel and gasoline because the speed ranges are not the same). Knowing that for a general public vehicle we seek to obtain a minimum jerk (also called over-acceleration, mathematical derivative of acceleration) so as not to shake the passengers too much, knowing the torque curve and the inertias is essential.
@@danielfranchette5547 engine produces work=ammount of force times angular distance (rotation) or power=force times speed of rotation. If an engine has huge inertia then measurements on the flywheel will be smaller. "Torque" curve (which is actually a work curve) may be more convenient if there is no way to change the power output of an engine at different speeds of a car (no gearbox). Still, comparing only power curves of two different engines installed in the similar cars we have a picture of their acceleration even without gearbox. And if we have a gearbox it almost totally neglects work data of an engine, since we can always have a very short first gear or final drive ratio to accelerate as fast as possible to peak power and keep shifting gears there. Torque is the only way to measure forces*leverage applied to a non moving object. If it moves then distance come into play and we dont use torque but work. When time/speed comes into play it is performance now and is measured by power, you cant measure it with work anymore.
@@danielfranchette5547 you describe mostly specific engineer solutions when building an engine, covering parts strain, vibrations, efficiency etc. Sure, torque is useful here.
woah so that's why electric freight locomotives seem to move smoother and faster than diesel ones specially watching them electric locomotives seem to move double decked cars more easily than the diesel one could even if they have same tonnage
2:48 no dude I don’t think it works like that Because it’s all about the combustion process in the engine not about how far the big end journal is, because you can change the cam profile of your engine to make it produce more torque than hp.
Sorry, I probably wasn't overly clear, what aspects of the combustion process affect the torque / horsepower balance? It's been a while since I made this video, but if I've made a mistake, I'll pin a correction comment.
The thing i wanna ask is how vehicles like trucks produce more torque than horsepower. I know that trucks have big engines because of longer strokes and use diesel because it produces more torque. But do things Like what the piston is made of or how heavy the piston is or the combustion power of the fuel affect torque in any way?
I understand. But at the same time I don't. :-)) Torque is the power used by piston to push on that rotating shaft. But... HP is how frequent a force is applied. But, then again, shouldn't it also matter against what force the engine works? The weight of the engine itself plus the car, the angle of the road etc.
First, torque is not that force that pushes the piston. Torque is not a force. Second, yes, engine's force overcomes all resistances and moves the car. The lighter the car the faster acceleration will be with the same engine, by 2nd Newton law.
So for an SUV(bmw x4), which weights 2 tons: diesel has 400nm 200 hp petrol has 350nm and 262hp What I understand from torque/nm is that if I put more weight on a petrol(5 people with luggage), the petrol will struggle and won't be that fast? Where diesel will not rev that much and will take it slow and handle a lot of weight. I mean you see the specs above, I'm a bit confused what are the pro and cons for that, both engines are 2 litre engines. I'm new to car concepts
Problem is, the car is not an engine. Between the engine and the road there are gear ratios and, most likely, they differ between diesel and gasoline options. If gasoline wins 0-100 acceleration, it will keep winning if you add weight to both cars because of the 2nd Newton law from where acceleration = force / mass.
petrol would not strugle it would just required higher rpm for generate the same thrust , disel be stronger at low to mid rpm in your egzample but petrol above mid rpm be dominant if you choice let say perfect gear at 100 km/h for overtaking some other vehicle and try accelerate to 140 km/h let say uphill with 5 pasangers onboard assuming both cars except gearbox and engine are the same so weight drag asf than petrol do it faster cos have more power 👌🏻 it would generate more contact path force cos watt :m/s = force as long as gearing be eprfect for both and peak power width quiet similar it be the disel from your egzample which be strugle more in such test ,the point is for daily riding where you dont want shifts like in race track and want stay on as low rpm as posibble the disel version be better cos its stronger at low and mid range rpm let say from idle whatever is idle rpm in this car let say 600 rpm to 3000 rpm os disel would have advantage in how much fprce it can generated pull some stuff on such low rpm easier be having more tprq power at this low rpm comapre to the dame low rpm petrol from your egzample the point is like im mention earlier if you reduce gear in petrol and use higher rpm where petrol have more power it now start generated more output force and tow heavy stuff easier than disel now get it ? very simple 😉👌🏻 whole confusion come from those id…ts who makes such video that they dont take into consideration speed factor what is lethal misteake 😉🤭they sibscribe everything like you could comapre 0-100 acceleration be one vehcile do 0-100 and some other be do 300-400 km/h and compare for both 0-100 km/h 😂🤮
Torque = moment = distance x force, Newton x metre (Nm), or ft x lbs, never ft/lbs.
That is my bad!
@@TMW_Photography Idź inie grzesz więcej
I was expecting millions of views with the quality of this video, keep up the good work bro!
Thank you!
I swear, out of all the videos that explain power and torque (which have many more views than this video) this one is the most clearly explained and complete. This video was really helpful. I'm glad I came across this video.
Thank you! I'm glad you found it informative.
I've been looking for a good explanation for a long time and this is the best I've seen so far!
I'm glad you found it helpful!
@@TMW_Photography I’ve seen at least 10 videos on this subject, this one finally explains it!
Bro. Me too. I've finally found a great explanation
I couldn't agree more
Wow! Thanks for the rundown on the physics behind torque and horsepower. I'm watching more videos about cars and how they work, but have definitely been lacking on combining this new knowledge with my limited knowledge of mechanics. Thanks for helping me begin to bridge the gap. And I loved the info on electric engines, too!
Glad you found it helpful
think of hp as income. and tq as hourly rate. rpm is hours worked...
much easier.
tq ($/hr) x rpm (hours) = salary/income (hp)
hp always wins
I have watched more videos explaining this subject than I care to admit, and finally, this is the video where it finally made sense.
Thank you so, so, so much for this!
I'm glad you found it helpful!
3:44 all i needed to know. Thank you
Superb video. But, let me share this here knowing it can uplift someone that comes across it. Effective financial management made me rich and it is all you need if you want to build a strong financial future tomorrow. I started with 1000USD, 3 years ago I invested in a diversified stock market and fast forward to now I am worth 500000USD and am currently finishing my 8 unit apartments. I'm only 35 years old. Diversified stock investments have always proven to be very profitable, especially with the help of experts.
I'm really impressed. At 35, i was worth a little over $200,000 from * in the stock market. But what you've done with your *finances* and numbers you worth, is pure genius.
*Investing* in diversified stocks is a real hustle that has made me . I have two active stock portfolios and hope to create a third, which will increase my total return on earnings to over 120000USD
You have done well. It's people like you who set the benchmark for people like us to know that achieving financial stability and transition of status from being comfortable to wealthy is possible with the right *investment* plan.
I'm curious, is *investing* in a diversified stock *market* a pretty lucrative venture? Can you share how you achieved these figures?
@@sarahtjoanne5300 Experience plays a key role when *investing* in diversified *stock markets*, which is why I have Rachel Hilda, whose experience has greatly helped me persevere in the diversified *stock market*. For three years she helped me grow my portfolio using her diversified knowledge of the financial *market*.
There are lot of videos on internet, but you made it really easy... I'm comparing with big channels like Donute Media.. your articulation is too good!
Thank you!
This is the video that FINALLY, I repeat _FINALLY_ taught me where engine torque actually comes from. The example of loosening a bolt with a wrench to define what torque is has been done by countless "what's torque" videos, and I understood what torque is alright, but I just couldn't transfer the concept to vehicles. My thought was "Ok, but when a car is moving, it's the other way around: you turn the wheels' center so that the wheel can rotate and the vehicle can move, you are not acting on the wheels like you'd do with the wrench". Those videos, at least the ones I've watched, missed the part at 2:35 - it all starts with the pistons being pushed by the working fluid (air-gas mixture, air-diesel mixture, steam...), and the pistons in turn push or pull their crankpins in the crankshaft, making the latter rotate. The pistons pushing the crankpins and rotating the 'shaft are like our jands pushing on the wrench to loosen (rotate) the bolt. It's then relatively easy to work your way to the wheels from this point!! Thanks for the video and the explanation!!!
I'm glad it helped you! Thank you for taking the time to leave a comment.
This video cleared my confusion of torque and hp inside a combustion engine, I was so lost. Thank you very much.
I'm glad it helped!
It is a common misconception to believe that a longer stroke generates higher torque. The complete physics and thermodynamics of it all are quite complex, but in general terms, for a given displacement, the longer stroke is offset by the smaller piston area on which the combustion gases apply pressure, which results in less force being applied. Truck engine make more torque because they are big: there is no substitute for displacement.
Also, a 300hp engine will be able to move the same heavy load up a hill at the exact same speed, be it a 8000rpm sports car engine or a big diesel truck engine, it's all in the gearing. Truck engines are "tuned for torque" simply for durability and fuel economy reasons. By being able to generate the desired power levels at low RPM, they can last way longer and consume less fuel in the process.
Torque has absolutely NOTHING to do with stroke, and is solely dependent on Pme, i.e. cylinder filling!
Great explanation.
Torque is an expression of twisting force with NO REGARD FOR SPEED. It could be at 0 rpm or 10,000 rpm.
Horsepower is a more complete expression of performance, taking both torque and speed into account.
As is common when speaking of car engines, torque is usually noted AT a particular speed. This is in fact all we need to compute HP, but the math is simply not completed. We could just as easily say that X engine makes 360 hp at 3500 rpm (its torque peak) and 500 hp at 6250 rpm (its hp peak). Graphing this curve really tells us a lot.
We can double HP by either doubling torque OR by doubling the rpm at which the same torque is produced. Or more realistically, by increasing BOTH factors to a lesser degree.
Assuming proper gearing, the engine with more horsepower will ultimately do work more quickly. OTOH, most of us don't operate street cars at their HP peak very often. It is unpleasant (to police at least) and hard on the engine. Low rpm and part throttle torque is useful in everyday cars because they spend so much of their time in that range.
Best explanation I've heard so far thanks!
I'm glad you found it helpful!
Horsepower at the engine is more important than torque at the engine. If you have horsepower at the engine, you can always use gearing (torque multiplication) to increase the torque. If all you have is torque, you CANNOT get extra power by modifying the gearing. Ever. That's physics.
in real driving conditions it's better have torque driving low rpms. if you think motorsport it's the opposite
@@mariocasinetti158true .
Quite theoretical, yet how come there is no excavator nor truck rev for torque, hmm..🤔
@@dudulin1359 Because they run all day, every day and need efficiency and longevity. Not because a higher revving engine "wouldn't work." It would work fine but it would be less efficient and would not last in the application.
Got it! Quite understandable, so sounds like the engine is like a tool, no such the best in all variations but the most suitable in certain conditions tho? Meaning not always the best seeking for high HP🤔
Horsepower is a UNIT of power. Torque is a measure of twisting forces. 1 horsepower equals 745.7 Watts. Life is easier if we avoid those old units.
Lets start with the basics
Force = mass x acceleration
Torque = Force x Distance
Work = Force x Distance
Power = Work ÷ Time
THERE U HAVE IT.
That’s the best explanation I’ve ever come across. The Narration and the visual aid provided a great way of understanding the whole process. Thank you very much.
Power is how fast you (or the engine) generate chunks of energy and torque is sort of how big are the chunks. The piston strokes are “stronger” with more torque. That’s half of the problem. The next problem is why small chunks at high rate is equivalent to high chunks at low rate. You can try on a bicycle, to go on a slope you can either use lower gear and low torque or high gear and push hard with the bicycle going the same speed in both cases. So with high torque you will use a high gear ratio. But what about high torque and low gear ratio. That can be done and the rpm will go up quickly so you will need to be capable of high rpm but high rpm and high torque simply means a lot more power so in that case you have a more powerful engine.
Another problem is trying to analyze the power curve. You can have high torque from low rpm. That also means high power not only torque at that low rpm and that makes the car relatively fast without needing to push the rpm high.
'chunks'. Please, take your talent elsewhere.
About the 'chunks of energy' verbiage; what you are saying seems consistent and clear, but it points to a common misunderstanding of power if I'm interpreting your meaning correctly. I sincerely want to help more people actually understand power. There are so many people who will have good ideas in vehicular engineering, and have drive to make stuff happen, but have a common and crippling misunderstanding of power. It's a really foundational thing to understand and unlocks a lot of doors.
You seem to be describing power as though it is equivalent to engine speed, as the rate of producing chunks of energy REGARDLESS of their size. In truth, power is the rate of producing chunks of energy INCLUSIVE of their size. Engine torque is "swallowed up" in the significance of power. It is (in one of it's many forms) simply rotational speed times torque. In your examples, you speak of power and torque as two different ways to achieve a particular level of performance. This is largely true for RPM and torque, but NOT true for power and torque in any way, ever. Because power is the product of torque and something dimensionally different (engine speed), power and torque are dimensionally incomparable. (Tangent: 5252 rpm has no physical significance at all)
To know the actual thrust force that an engine is imparting to any wheel-driven vehicle at some moment while it is moving, all we need to know is the engine's power at that moment. We know a little of that power is lost in the transmission / final drive / tires, but besides these, thrust depends only on power and vehicle speed at that moment.
If we don't know the engine power, then even if we know the torque the engine is producing at that moment, we can only guess at thrust it's providing, because we must NOT know the mechanical advantage (gearing and wheel diameter) that connect that engine to the road - basically the ratio of distance rolled per engine revolution). If we did, then we do know power, because that ratio together with the vehicle speed dictates the engine speed. All this assumes that the tires and clutch aren't slipping, but that's really the only significant assumption.
Is this making sense?
Good use of graphs to explain that hp and torque aren't constant when it comes to motors.
Thanks!
Think about it this way, torque is the power of the punches, rpm is how fast you can punch, and horsepower is the total damage.
I am glad that i came across this video. Out of all the multiple vids, i found this one to be the simplest to understand. Thank you!
Great video! Do you still have a link to the outro music? I think the original is gone. I was jamming after your awesome video and wanted to keep the vibe up
Sure, he's a great artist, find it here:
czcams.com/video/ebIPyaJTMog/video.html
Great explanation now i finaly understand !
Great work done here video quality is 11/10
Never ceases to amaze me how many people get this wrong. Torque is measured in lb-ft not ft-lbs. Ft-lbs is a measure of energy. T=FxR, F for force in lbs and R for radius in ft... lb-ft. Sorry, I don´t want to be ´that guy´ but this issue grinds my gears, so to speak.
Incredible. Wish i could buy u a drink. Thanks. Torque and its formula is as eady as 2+2, but understanding it related to the engine gave me problems. 10 vids in, I found the answer thanks so much
I'm glad you found it helpful!
Well explained 👏👏👏
Thank you
Best video on torque and horsepower on CZcams
Thank you! I'm glad you found it helpful
This has really helped. Thank you.
Amazing explanation..! Thank you very much.
You are welcome!
It all starts with Torque. An electric motor can produce all its torque at 0 rpm. That means 0 horsepower. It’d be the same as pulling maximum force on a spanner but it doesn’t budge. All torque and no work so no power. But, the opposite can never be true.
Best video i've seen on this particular topic. Thanks
Helped, thanks
It does not explain why the torque decreases yet the total power increases this should be explained. Engine friction increases which decreases torque with higher revs, but despite less torque the extra revolutions still give more power. Example less power per engine revolution but twice as many revolutions still give more usable power in a minute. Engine design and breathing size all alter the torque curve
I think there's a lot of confusion in the racing / sim racing world about torque vs power. For instance, many games give you a graph of torque and horsepower, and we are often told to pay more attention to torque (regarding when to shift) because that is where acceleration occurs. But I still get confused, because they say power is the ability to move a mass quickly, so doesn't that directly imply acceleration? Plus horsepower is always the first spec about a car that is bragged about. I'm also curious how overcoming friction ties into this. As a racer, I want to understand this better, but the information still conflicts in my head.
Only horsepower counts..
Well, yes power is what is needed to accelerate quickly. But it's more complicated than that. In order to accelerate a mass at any given rate, a force is needed. In a car's case, that force comes as the push that the tires give to the car. That comes from torque. So in order to accelerate a car quickly, a certain amount of torque is needed. In order for the car to accelerate at a constant rate, that torque is needed all the time (actually in the real world, as a car goes faster, more torque is needed to keep the acceleration rate the same). Which means the producer of that torque needs to produce that torque at an ever increasing rate. You can think of it like pushing against something really heavy to move it; as soon as what you're pushing moves, you have to move with it in order to keep pushing on it with the same force. The faster it moves, the faster you have to move. That is what power is: the rate at which a push happens. We tend to think of things like the example I just gave: humans doing work. The pushing force that different humans can generate varies widely: a huge man can push way more than a child, but the different rates we can push at are not all that great: we all move at close to the same rate. So we get into this stupid debate about whether torque or power is more important. Machines don't work like humans, however. With gearing, the force that machines are able to exert on objects is limited only by the strength of materials. So, it is the rate at which a force can be implemented that matters with machines. That is the definition of power. In mechanical systems, it is power that matters. Power, and gearing or force manipulation. With enough manipulating of force, any mass can be moved. The rate that it can be moved is constrained by the power input into the system.
The author of this video made a couple small mistakes that might be confusing. All you have to remember is that when it comes to mechanical systems:
Power is what matters.
Friction is just another force on the system, same as inertia or wind resistance.
@@tylerfb1 I like your analogy of looking at a linear motion (with Push and Velocity), to intuitively imagine how an equivalent rotational motion (with Torque and RPM) works. It is now clear to me why it's not just important for a car engine to deliver Torque (push), but to be able to deliver similar levels of torque at higher RPMs (velocity) -> ignoring wind-resistance for now.
However, there's sometime that's still un-intuitive to me:
Preface: I understand that Engine (Crankshaft) Torque and RPM "need not be the same" as the transmission (Wheel) Torque and RPM respectively.
If we can manipulate torque ("force manipulation") by using gears to any extent, does that mean that I can fit a family car's engine to a huge truck, and tune the gear-ratios in such a way, that the small engine can still move the huge load? Or will the engine simply stall, because it cannot turn the wheels of such a heavy truck?
Hope you can explain this to me in an intuitive way.
Rephrased question: Is it even important for a car engine to be able to offer "good" torque, if we can simply multiply the output torque on the wheels, using appropriate right gears?
@@nischalshetty2411 yes you can use a family car engine in a truck, and further more, if it has the same power as the big truck engine, it will theoretically accelerate the truck at the same rate! But there’s a big “if” there: if we can manipulate torque all we want without penalty. In the real world, we can’t do that.
My comment is meant to help wrap your head around the theoretical concepts at play with power and torque. What is left out is all the other real-world implications.
Engineering is about striking the balance between many, often competing, requirements. The transmission that would be required to implement a car motor in a truck would be large, heavy, and expensive: in short impractical.
Efficiency, maintenance costs, and service life are very important considerations in commercial vehicles. Diesel truck motors are very efficient in their applications. They create power at low RPM, which means lower maintenance and higher service life when compared to equal gas engines and certainly a car motor used in a truck. It also means they turn more fuel energy into motion then an equivalent gasoline engine (they use less fuel for the same power output). They have lots of torque, which means they don’t need extreme gear reductions to create the needed wheel torque. Even the packaging: how much space an engine/transmission take up and how they are mounted to the vehicle is a requirement of concern.
So, while it is true that power input is the only concern as far as acceleration and motion are concerned, in a practical application, there is so much more to the equation. That’s why the engines we see in use in all these different applications are the engines we use in those applications. 😊
@@nischalshetty2411 let me more directly answer your question, and give you a picture.
Let’s say you had a transmission that turned the wheels one revolution for each 100,000 revolutions of the engine. Even if the engine was rigidly coupled to the transmission input, you start that engine, and rev it to 10,000 rpm for ten minutes before the wheels turn once. How much force would you have to hold those wheels with before you were able to stop the engine? If the engine makes 500 ft lbs at 10,000 rpm, it would take 50 million ft lbs to stop it. That’s the weight of 50 A380s.
I hope you can see that with infinite torque manipulation, a simple family car motor could easily move a truck without stalling. 😊
So torque gets you started and hp maintains?
no.
the amount of tq at the wheel to rotate something is called tq. that doesnt change
but how much tq you can apply based on how fast the car is going based on the road is called hp.
the faster you are travelling, and you want to make the same wheel tq, you need more hp.
this is why trucks always make lots of tq. the relationship of these two things is the whole point...
a 1hp car, can infact make a "technically" infinite amount of tq, but at an infinitely slow speed...
a large amount of hp can do "techinically" the same thing at an ever increasing higher speed of the vehicle.
this is why the trap speed of a mass going down the 1/4 mile is based on hp, not tq.
hope this helps
The length of them *connecting rod* matters ..
*Long* strokes vs *short* strokes
That's what she said.
well of couse this matters. but it is literally changing one variable and affecting another. longer strokes means more tq per explosion, but you reduce your rpms. so one affects the others. the real problem is weight balance, harmonic balance and wha you want the motor to do...
@@chaztitan6457 .. .. . The rest be rested on them gears inside a fluidity box.
I'm guessing.
Sure, but also long strokes means the pressure inside the cylinder can be released later. As the piston travels down the pressure drops so basically you have an initial high torque then towards the end of the travel the force of the piston drops more and the torque is reduced. Anyway on average there will be more torque but these engines will produce less power (if not using forced induction of course, in that case torque goes up a lot more). It’s basically a configuration for economy because you use extra energy left in the cylinder. With short stroke you will also be able of higher rpm. That the case for sports engines with 7-9k rpm
@@rotorblade9508 we all agree that long strokes create more tq. simply by the crank arm is longer.
i really dont understand what you are arguing for or against. you seem to agree
why not just thumbs up or make a counter argument.
0:11 butler performance? nice, pontiac engines love making torque low
Let me ask a question - does torque affect fuel consumption? If in my engine at 1750 rpm is the max torque (200 nm), and at 2500 it’s 150 nm, it means that driving at 1750 will consume less fuel than on 2500 rpm?
Yes to your question.
Still ,if you need to save more fuel per distance, don't drive at peak torque revs
No not really. You will only get the maximum torque for any given revs, if you put your foot full on the gas. If you do that, then unless you're going up a steep hill you are going to accelerate and the revs will increase anyway .
Obviously putting your foot on the gas does use more fuel, but you can maintain revs at say 1750rpm by easing off the gas and therefore lowering the torque output to just sufficient to keep going at the same speed . Generally though you will get the best fuel efficiency from most petrol engines in top gear at around 2000rpm.
@@smiler447 I’ve learnd how it works, it seems that it depends over if the engine has turbocharger. If so, keeping revs lower will give better fuel consumption, at naturally aspirated engine it’s like you’ve said
Hopefully we should keep electric cars away from bad drivers, with that instant torque and high power output...
A lb isn't a measure of force. It should be lbf - the force of 1lb under gravitational acceleration (a pedant speaks)
More piston = more hp and less piston = more torque
How is horsepower increased or decreased? I mean how to design an engine for horsepower?
That's quite a complex question, and I've added it to my list of videos to do.
@@TMW_Photography Thanks. Looking forward for it.
@@FaizanAli-op2xe best example is a history of chevy small block engine. Compare LT1 5.7L for Caprice with 260hp, Firebird with 275hp and Corvette with 300hp. So #1 reason is shifting torque along the rpm scale higher (for more power) or lower (for better fuel efficiency). Torque shows an efficiency of combustion cycle. ICE is an air pump that works at different speeds (750-6500rpm), and air feeding can't be optimised for such a wide range. Unless you have a VVT, VVL and variable intake geometry technology.
@@IgorArkin Thanks for the info and taking out the time to write the comment. Appreciate the effort.
The simplest way is to make it rev higher.
power (watt) = torque (Newton meter) * angular speed (radian / s = 2 * pi * rpm / 60).
torque is a parameter of power. so do you need torque or power? answer both my general.
the interest of the couple only appears on the acceleration aspect
inertia * acceleration = motor torque - resistant torque (simplified presentation). If you want good acceleration, decrease the inertias (moving masses) and increase the engine torque, the resistive torque being fixed by the tires, aerodynamics and the slope of the road.
if you want to go fast you need power to obtain equal engine torque = resistant torque at cruising speed (at high speed the aerodynamic effects are enormous)
as explained, electric motors have a much more favorable torque versus speed curve than thermal motors.
When you introduce torque, force and leverage become obsolete. You got 400nm and you dont care if it comes from 3.0 diesel (leverage) or from 5.7 gasoline (force). 1kg of steel = 1kg of cotton candy.
Same thing with power. When power is introduced torque becomes obsolete. Power is speed times acceleration divided by mass. There is no torque here. It is somewhere inside power and we dont care about it.
@@IgorArkin The couple is interesting when we are interested in dynamic regimes (fundamental relation of dynamics). For a rotational movement J * angular acc = Motor torque-resistant torque (with J moment of inertia in kg.m2, acc in rad / s2, Torques in Nm). So knowing only the power of an engine is not enough, you also need the torque curve to determine the acceleration capacities.
The dynamic behavior will also depend on the moment of inertia of the moving parts, so the choice of materials and their shape have a significant influence on performance.
So when you tell me that the torque of a diesel is the same as for a gasoline engine, it is very likely that the moving parts of the diesel are heavier than for the gasoline engine so that the inertias are greater therefore that the accelerations are less with the same torque.
In position control systems, motors are dimensioned in torque rather than in power with rotor shapes reducing inertia to obtain great reactivity.
@@IgorArkin To continue the explanations, the torque curve will determine the design of the gearbox and its staging (not the same between diesel and gasoline because the speed ranges are not the same).
Knowing that for a general public vehicle we seek to obtain a minimum jerk (also called over-acceleration, mathematical derivative of acceleration) so as not to shake the passengers too much, knowing the torque curve and the inertias is essential.
@@danielfranchette5547 engine produces work=ammount of force times angular distance (rotation) or power=force times speed of rotation. If an engine has huge inertia then measurements on the flywheel will be smaller. "Torque" curve (which is actually a work curve) may be more convenient if there is no way to change the power output of an engine at different speeds of a car (no gearbox). Still, comparing only power curves of two different engines installed in the similar cars we have a picture of their acceleration even without gearbox.
And if we have a gearbox it almost totally neglects work data of an engine, since we can always have a very short first gear or final drive ratio to accelerate as fast as possible to peak power and keep shifting gears there. Torque is the only way to measure forces*leverage applied to a non moving object. If it moves then distance come into play and we dont use torque but work. When time/speed comes into play it is performance now and is measured by power, you cant measure it with work anymore.
@@danielfranchette5547 you describe mostly specific engineer solutions when building an engine, covering parts strain, vibrations, efficiency etc. Sure, torque is useful here.
Ninja zx25r 4 cylinder = 51hp and 22.9 Nm and Ninja 400 2 cylinder = 45 hp and 38 Nm
"I'm going to make it easy on my American viewers and use Imperial units.... anyway here's my spanner"
woah so that's why electric freight locomotives seem to move smoother and faster than diesel ones specially watching them electric locomotives seem to move double decked cars more easily than the diesel one could even if they have same tonnage
I am far from sure, but it was my understanding that diesel locomotives actually put their power down via electric motors.
2:48 no dude I don’t think it works like that
Because it’s all about the combustion process in the engine not about how far the big end journal is, because you can change the cam profile of your engine to make it produce more torque than hp.
Could you elaborate please?
@@TMW_Photography I’m saying 2:48 is completely wrong
That’s not how torque works in an engine
It’s determined by the combustion process in the engine
Sorry, I probably wasn't overly clear, what aspects of the combustion process affect the torque / horsepower balance? It's been a while since I made this video, but if I've made a mistake, I'll pin a correction comment.
@@TMW_Photography I can’t show you examples on what I’m talking about because this CZcams keeps deleting my comments
Oh, that's a little weird.
The thing i wanna ask is how vehicles like trucks produce more torque than horsepower. I know that trucks have big engines because of longer strokes and use diesel because it produces more torque. But do things Like what the piston is made of or how heavy the piston is or the combustion power of the fuel affect torque in any way?
how did you do it can you share with me , thank you
If you mean the animations, I use Adobe animate, and build the assets from scratch in Inkscape.
how can torque increase in the graph if the length of the piston and crank length remains the same?
5:18 name of this car?
Oreca 07, run by the United Auto sports team iirc.
Finally
❤
perfect!
I understand. But at the same time I don't.
:-))
Torque is the power used by piston to push on that rotating shaft. But... HP is how frequent a force is applied. But, then again, shouldn't it also matter against what force the engine works? The weight of the engine itself plus the car, the angle of the road etc.
First, torque is not that force that pushes the piston. Torque is not a force.
Second, yes, engine's force overcomes all resistances and moves the car. The lighter the car the faster acceleration will be with the same engine, by 2nd Newton law.
Easier to understand when you use imperial units? You must be speaking to Americans only!
Perfect
eh?
So for an SUV(bmw x4), which weights 2 tons:
diesel has 400nm 200 hp
petrol has 350nm and 262hp
What I understand from torque/nm is that if I put more weight on a petrol(5 people with luggage), the petrol will struggle and won't be that fast? Where diesel will not rev that much and will take it slow and handle a lot of weight.
I mean you see the specs above, I'm a bit confused what are the pro and cons for that, both engines are 2 litre engines. I'm new to car concepts
Problem is, the car is not an engine. Between the engine and the road there are gear ratios and, most likely, they differ between diesel and gasoline options. If gasoline wins 0-100 acceleration, it will keep winning if you add weight to both cars because of the 2nd Newton law from where acceleration = force / mass.
petrol would not strugle it would just required higher rpm for generate the same thrust , disel be stronger at low to mid rpm in your egzample but petrol above mid rpm be dominant if you choice let say perfect gear at 100 km/h for overtaking some other vehicle and try accelerate to 140 km/h let say uphill with 5 pasangers onboard assuming both cars except gearbox and engine are the same so weight drag asf than petrol do it faster cos have more power 👌🏻 it would generate more contact path force cos watt :m/s = force as long as gearing be eprfect for both and peak power width quiet similar it be the disel from your egzample which be strugle more in such test ,the point is for daily riding where you dont want shifts like in race track and want stay on as low rpm as posibble the disel version be better cos its stronger at low and mid range rpm let say from idle whatever is idle rpm in this car let say 600 rpm to 3000 rpm os disel would have advantage in how much fprce it can generated pull some stuff on such low rpm easier be having more tprq power at this low rpm comapre to the dame low rpm petrol from your egzample the point is like im mention earlier if you reduce gear in petrol and use higher rpm where petrol have more power it now start generated more output force and tow heavy stuff easier than disel now get it ? very simple 😉👌🏻 whole confusion come from those id…ts who makes such video that they dont take into consideration speed factor what is lethal misteake 😉🤭they sibscribe everything like you could comapre 0-100 acceleration be one vehcile do 0-100 and some other be do 300-400 km/h and compare for both 0-100 km/h 😂🤮
how can torque increase in the graph if the length of the piston and crank length remains the same?
Torque is not only affected by length of the crank which leaves us with force being different along the rev range.