Changing Tire Sizes: For Rally, Racing, and the Street
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- čas přidán 9. 07. 2024
- Learn how to read and understand tire sizes, as well as how to make constructive changes to tire sizes on different vehicles. Depending on your vehicle and your intent, you may choose to add wider or narrower tires, taller or shorter tires, and/or tires with more or less aspect ratio. All of these changes will affect your car's performance and handling, so knowing what you can expect from different potential changes is critical in making proper tire buying decisions.
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Yeah I'm into fitness. Fittin' this 175/60/15 gravel under my stock suspension Fiesta ST!
thats boomer humour from a 30 year old right there
@@tdp2612 correct! Am 32 years old 😄
What size wheels and tires do u have dash-n-cars?? I just got a 17 FiST and im looking for 15" winters. After my research im looking at 15x7et40 sparco terra with 195/55/r15 nokian hakka r3's .
@@billydotlast I have an entire garage of tires for Rally, those should work great for winter tires though. Gravel/stage tires run huge compared to a DOT tire.
@@DashnCars cheers mate! I have a garage full of subie tires and rims but the fiesta is shamefully sitting on summers until i can figure it out. Im pulling the trigger on this setup tommorow i think
The "R" stands for radial as in the tire's cord construction. With so few bias-ply tires for sale these days, that "R" has become ubiquitous, but it still means radial tire.
I always knew snow rally cars often run insanely skinny tires and wheels, and I knew it was to cut down into the firmer ground beneath the snow, as well as to kind of act like sled skis or rudders more than actual wheels, but it never occurred to me that it also benefits the car by significantly reducing wheel and tire weight, which really helps combat the increased weight of heavy duty rally tires and rims! My mind feels expanded.
Seen so many tire videos and I still learned something new! Thank guys!!!! Particularly rally tires and how much MORE reinforcements are in the sidewall... HOLY MOLY
Thanks Jason!
You can get about a fifth of that ribbed/reinforced gravel rally tire sidewall strength just by opting for a XL load rated winter tire over an SL rated one, IF that is offered in the size you need. ;)
After hearing their talk about the sidewall size and how for performance you'd want a thinner side wall, I just wonder why F1 uses 13 inch wheels with really fat sidewalls.
Wyatt helping us being fast boys.
noice
Great information and excellent explanations! Keep up the good work!
I love videos like this. I'd suggest anyone new into cars watch it, great explanations.
Thanks for that explination Team
You guys say a taller tire will result in lower fuel economy. What actually happens is you'll get lower CITY fuel economy due to heavier rotating mass, while HWY fuel economy will be higher. This is because a taller tire will essentially gear up your final drive ratio, allowing your car to travel further on every revolution. Yes, you do get slightly more frontal area with a taller tire, but IIRC the gearing makes up for that. Folk wisdom usually says that fuel economy is primarily determined by weight, but in reality aerodynamics and gearing play a HUGE role, especially above inner city speeds. Love the channel. Love the driving instruction videos in particular. I just wanted to pipe up about this to clear the air a bit!
True! We live in the mountains here and get so used to it that we don't take everything into consideration as much as we should. Around here, a taller tire will generally lower MPG going up and down all the hills but on flat highway you're absolutely correct. Thank you for the addition, these are the comments we love seeing on this channel!
@@Teamoneilrally For sure. I love the channel. If you're taking requests at all, I'd love to see interviews with people who run historic (say pre-fuel injection) rally cars in ARA/NASA. I know there are a few around, and would love to hear a bit about their experiences. Thanks for existing! I hope someday to be able to come do the school myself.
Next video, gravel tire in the snow vs snow tire (no studs). Both run on the same rally route.
Yes. The gravel tire might fall apart, but would be cool to see
Great info. So many videos missed all this info!
Perfect timing yall read my mind
Nice topic and video, would love more depth next! Especially regarding the effect of different rim and tire width matching options and how I believe a smaller aspect ratio allows for less difference in that regard
Best video on tire size ever$!
Nice lesson. Thanks
Great video fellas
great video...one thing I just learned with my 185 55 16 tires is that they don't survive winter potholes very well...I'm going 185 70 r14 for winter from now on...comfy ride and a lot of sidewall for maximal pothole protection! And for summer...I'm thinking of going 185 65 r14...my older Honda FIT always had a zippier feel, and I'm pretty sure it was because of the smaller tires. LIghter too...so perhaps I'll get better mpg.
The roads are pretty rough where I live in California, so upgraded suspension and rally rims/tires may be a good choice, but it's expensive and will slow my Focus down. The good news is that I get plenty of practice at weight transfer to shift my car's weight away from holes/cracks/exposed railway tracks/ect. Good to learn until I can make vehicle changes I guess, but my wife has to grab the cornering handle a lot. Lol. 🚗💨💨💨🙅
The True you mean the oh shit handle right
@@funnypranker34 If you prefer, then yeah.
Please do (will it rally suzuki xl7 2002) and what do you think about it.
I see more people run wider tires in the snow and i try to explain its still water, and your driving on it. You need to cut through it to get actually traction, on hard packed deep snow wide might help but you still gotta dig in a bit.
Emphasize shouldn't be put on speedo reading change, as, if anything, with taller then stock size tire .. speedo actually will lie less :) (as due probably some silent car manufacturer agreement, even with stock tire sizing, speedos on most not ancient cars show higher then actual speed. Anybody can compare speedo vs gps in some satnav app).
What may matter more then speedo change - change in overall gearing ratio, especially on underpowered cars, which might be unwished thing, and potentially hurting acceleration more then eg. extra weight (but possibly making slightly better fuel mileage). But then there might be wished change of increased ground clearance in simple, not modding anything in suspension, way (which sometimes might be aim for, eg. in winter & rally use on some already low as stock cars), give pros of taller tires (more compliant ride/better wheel protection) w/o having to buy another wheel set.
Worth also noting few rules of thumb. For example if one wishes to keep tire diameter somewhat same, if one changes one sizing number (width/profile height/wheel size) by one notch, worth changing another by one notch in opposite way (or if changing two things at a time, then "compensate" by two notches third). Moving to bigger wheels by 1"? At same width reduce by one notch profile height (5%). Moving to narrower tires on same wheels by one step (10mm)? Rise profile height by one step (5%). Narrower by two steps (20mm) but on smaller wheels by 1"? Similar diameter will be with profile height increase by one notch. Usually said as "safe" change for different tire sizing w/o much changes to speedo reading &gearing ratio (IF that is aim, unlike intentional choice of eg. taller tires for extra ground clearance), if overall diameter(/circumference/speed variance) is kept within some +/- 2-2.5%. Another rule of thumb - tire model/type/compound matters more grip wise then width.
my truck came stock with 225/75-16 on it, and that is what was on it when i bought it. everybody was passing me all the time like i was grandpa. Then i bought a set of 285/75-16 and it was pretty close. I was showing about 2.5mph slow on the speedo compared to gps at 70mph. now i have 265/75-16 and it is dead on. so....? i think maybe they calibrated the speedometers for one size tire only, and just said, well, thats gonna be close enough lol
forgot to mention braking performance. That was actually the first thing i noticed when going with much larger tires. the braking performance went way down. the larger diameter tire hase more leverage against the brakes rendering them less effective. and the same goes the other way for acceleration, larger diameter reduces your gear ratio and total torque. this was not much of an issue for me, but i did notice the braking immediately!
Can you guys do a video on measuring with simple tools (tape measure and straight edge) to find how big /wide / offset a wheel tire combo you can fit? I usually search the web for what seemed to work for most but I'm always wondering if I left some on the table.
Depending how handy you are there are a couple solid options. There are tools you can buy to do this which can be a bit pricy. Or you can build one by taking a price of wood or metal and bolt it to your studs and have it as far out as the tallest size you are looking at then bolt onto that piece (preferably something you can shorten easily) which can be accomplished by cutting a slot that can slide along where you bolt it on. Then set it as wide/deep as you are looking to go and spin around and check for clearance with the wheel centered all the way left and right and as much in between as necessary.
steelies... 175/65/r14 and my 95hp fiesta brings a lot of fun in winter ;) for summer dreaming about Autec Wizard with 195/50/r15 - they weight nothing!
and in summer, I would assume the wider tire would allow better grip...but would also result in higher MPG? Not sure if you covered that in your vid.
So in your professional opinion what is the best snow tire / all season or all-terrain tire for 235-70 r16 or even r15? I want maximum grip in snow/ice. But on the same tire I also want good performance on dry roads and rainy days as well as dirt.
Is it better for thick or thin tyres in gravel applications?
Thanks Team O'Neil !!! What size wheels and tires do you guys use on the fiesta ST in the winter/ rallyx setup.
I am having a rough time finding a definite answer. I want a 15" winter wheel
I run General Altimax Arctic winters in a 195/60-15 XL load rating, mounted on 15x7 method MR501VT (LONG gone/discontinued in our 4x108 PCD, the Sparco Terras would have been my second choice since I could not wait the 6+ months to get the 'real' {Braid/Speedline} gravel wheels) on mine, for winter/working/volunteering on ARA rallies.
These do NOT rub on the factory suspension, AT ALL, under any circumstances/scenarios. :)
IF I were competing in SCCA Rallycross, or IF I had ANY secure way to store the street wheel/tires while at the events (most hotels FORBID this in their rooms), I would get a set of dedicated gravel wheels/tires to use, most likely either Speedline Corse 2112s or Braid Acropolis with some sort of semi-affordable, 175/65-15 gravel tire on them
13:11 what is the rubber looking strip under the sill?
Where can an average schmo like me get rally tires? I haven’t seen that option on tire rack?
the internet is always the best bet
What tire would you recommend for ripping up logging roads for fun once or twice a month in an otherwise stock Outback daily driver? This on roads with some #2 crushed rock that punctures street tires usually within a mile or two? Rally race tires are out of the question.... tried that once already with Kumhos. They were worn out by 5,000 miles, most of which was on the street.
I am moving to the Yukon. I'm getting an 11 WRX. I will be traveling from Hanes junction to Hanes Alaska regularly. I'm going to be doing highway and off-road I have not been in a rally school but I would like to attend. Which size tire would probably be best for me I do like street performance. But I want to be smart. Thank you for the videos 😎
u r awesome
whats the setup on that fiesta on the back??
Hi, can i replace my 285/45-22 with 275/50-22 on an escalade for better quality? Will it fit? Thanks
Who’s got the “right” count 🙃
I read elsewhere that changing tire size will affect electronic calculations being made by the computer in your car, especially those that do fuel economy management. Is that true?
I have a 2019 Ford Explorer XLT tire size 245/60R18 and want try to put on All terrain what size do I get I look online but none match help
I Wont to lower my wheel size on my F-150 lower the truck to the ground with a wider tire. all I see is people getting larger tires and wheels. the factory wheels are 16 tires p-235/70 R16 .would like to put some 15 in. Cragar wheels with 60 series tires. Can I get adapters to do that?
or would it take changing rotors out. it has disk brakes all around. 2001
Vid on regrooving?
Any thoughts on the appropriate tire size vs. weight of the vehicle for off road? I.E. the right pressure between the ground and tire contact patch.
I think changing tire pressure has a way bigger effect on contact patcy/ ground pressure than changing tire size...
Ok so whats the size on that fiesta it looks awsome? And what size rims?
Those are the LONG GONE/discontinued in that application, 15x7, 4x108 PCD, 48 ET, Method MR501VT 'supposedly' gravel rally spec/strength wheels, same as I have on my Fiesta ST, only in black. :)
I cannot increase the magnification enough to read which tires they are using on them, nor see the side walls clearly enough to see if they are ribbed side wall gravel tires. ???
Is the narrower snow tire noticeably better outside of racing/ timed laps? I was debating narrower snow tires, but everyone said it is negligable...so I stayed with OEM width, but 1" smaller wheel. I already had an extra set of wheels, so it didn't seem worth spending the money when everybody seemed to agree it doesn't make a real difference...
If you do A LOT of driving in snow and ice, it might be worth it next time, but don't feel like you're missing out on a night-and-day difference. Even staying with the OEM width, you can go on tirerack.com and search your size, then for each winter tire under "Specs" they give the actual tread width. Compare a few and sometimes there's a big difference, like a 195 Blizzak WS90 is almost a half inch of tread wider than a 195 Yokohama iG52C.
Should you use a wider or more narrow tire for gravel?
Usually close to stock, but if it's wet you might want narrower, or dry and packed you would benefit from a little wider. Most rally teams will pick a happy medium and just have one gravel tire size then groove the tires if it rains... But some have "normal" tires and narrower "wet" tires. It's definitely a budget question, because every spare tire has to be mounted on a wheel and ready to go, and that gets expensive quickly.
👍👍👍
Great video, is there any way to get to know the actual contact patch width of a tire before having it the possibility to measure it? Im trying to find the smallest contact patch 195/65-15 tire for this winter...
Go on tire rack, search for your size and then when you look at individual tires, scroll down under the pic and click on "Specs" and they list the actual tread width. Here's the iG53 that size just as an example: www.tirerack.com/tires/tires.jsp?tireMake=Yokohama&tireModel=iceGUARD+iG53&partnum=965TR5IG53&vehicleSearch=false&fromCompare1=yes
Quick question - Let's assume I'm running the same tire size for summer and winter tires. Should I keep the pressure the same (as on the door jamb) on the winter tires, increase pressure or decrease pressure?
I am curious as well. Colder temperature means lower air pressure, so maybe you want to add air to keep tires inflated. But cold also means colder rubber, and tires will take longer to get up to ideal operating temperature for peak grip, and lower pressure tires warm up faster, so maybe you want to keep pressure lower, otherwise too much pressure and your tires will never warm up? I have no idea.
Short answer: most people run the same tire pressure in the summer and winter. Long answer: Tires change 1-2 PSI every 10 degrees F anyway (depending on tire size) so 32 PSI at 50 degrees could be down in the mid 20s PSI at 0 degrees. This means your best bet is usually to figure out what the ballpark average winter temp is in your area, and set the pressures at that temp. If you do get into a snowstorm or just want a little more grip, you can air down a little and it will make a noticeable improvement... Actually here's a video we made for off-road truck pressures but it shows exactly what you're looking for: czcams.com/video/KXAKVyKYJBw/video.html
@@Teamoneilrally Thanks! Unfortunately I live in Denver where the ballpark temp could be anywhere between 75 and 25 (Fahrenheit) depending on the day. :D I'll just keep an eye on pressures and adjust when it gets cold.
@@ChadGeidel Higher pressure is the answer. How much of your tire is in contact with the ground is inversely proportional to tire pressure. On ice you want more pressure on less area to push into it. You also want the tire to stay cold, a warm tire will melt the ice/snow making it wet and a lot more slick.
Right -right- *RIGHT* -Right-
So on my sports car, can I change the OEM 245 50 17 with 245 45 17, to bring the center of gravity lower and have better cornering, without significantly messing up anything else?
A little Negative camber will greatly increase your cornering without changing anything else
@@jordankelly4684 Thanks and update. I did it. Looks fine and better.
@@samsen3965 glad to hear it man. Stay safe, enjoy the car
How to get into rally racing?
I really want to try it, but do i need a license??? Or do i need a fully built car? Can i get into rally racing on a seriously tight budget
Whats the requirements???
I live in the netherlands so there will be differences but what are the things that should be the same everywhere????
czcams.com/video/BXJAA4f6Eag/video.html
You definitely can get into racing on a tight budget, the easiest way is to start of at rallycross or whatever the Dutch equivalent is. Budget cars in open areas driving around parking cones, it's the perfect way to start cheap and get a lot of skills quickly.
Can someone please help me with my questions
97 Astro, stock 215/75 15 to optional 235/65/15. What would be noticed in city driving/handling, safety while cornering (rollover?), and fuel consumption
It's not for racing, but I have to order the tires either way so I'm wondering which size I should order?
Is there an easy way to find out if the optional fe2 suspension package is installed? There's zero paperwork to reference.
Thank you anyone in advance
This is a fantastic resource, I entered the sizes in question but you can change to any size you'd like
www.tacomaworld.com/tirecalc?tires=215-75r15-235-65r15
Any time you go wider and less sidewall you'll get a little more pavement performance
If you're driving in the city mostly it seems like a good change
Rollover safety will not change dramatically at all
If you were considering a WILD change in size maybe, but this should be perfectly safe
Especially if they came as an option on the same vehicle
@@Teamoneilrally thank you very much for the quick reply.
That is an awesome reference, I will be using that again and again for sure.
What about the FE2 suspension kit? Is there an easy way for someone to see if it's installed or would it require a mechanics know-how?
A dealer could probably tell you from the VIN number?
Or maybe google the VIN number and see if you can find the options?
I'm gonna downsize my AWD Toyota Venza from 20s to 17s
Luxurious ride like Rolls Royce or fast time like f1. Can't have both. A Rolls Royce soft set up and slow or f1 hard set up feel every rock on the road but huge amount of traction. A true racer will know what get around corners faster... hopefully you don't try compromising that will make you slow, unomfortable and never happy with the car
Can have both, with no smooth ride there is no traction. I think you meant comfort, also low profile doesn't necessarily equal good feedback and vice versa.
180 is the same as 185?
The tire width of 180 and 185 are not the same but the difference between those two is minimal.
Tire circumference is your true final drive ratio
Ive always hated the metric scale in tire sizing.
Ok boomer
A boomer from 2000. Stfu. That was never funny.
I prefer metric over imperial system on everything, but the % thing indicating the profile is stupid. They should go mm between walls/mm of actual thread/sidewall height in mm/rim diameter, that would be easier to choose which tyre you want
Trevon Prabhat congrats ya fucking normo, you’ve killed it...
@@phrodendekia well, youre a bit biased based on how you spell tire lol.
That explains why people with lifted trucks are always riding my ass when I'm driving 15 over the speed limit
Wbam, Hi!
What's up! Thanks for being here.
@@Teamoneilrally I'm amazed I always thought wider tyres did better in snow.. But the thinner one cutting through like a sawblade makes much more sense 😂 great vid so far 💕
@@UndeadNaziKilla If you had to drive on top of extremely deep snow in the backcountry or something you'd need very big wide balloony tires like you would for driving on sand, but for "normal" winter driving most of the time narrow is the answer.
@@Teamoneilrally Hey quick question, on dry tarmac is it always better to have wider tires since that increases the contact patch? It'd make sense to do so to me.
Nevermind I'm an idiot you literally say that in the video -_-
ᕼI
Good morning!
Hah 500th like here😂
willtheyfit.com for calculators
Weight is the biggest contributor to shit performance. In my tacoma with its weak 3.5, I went duratrac load c, while everyone else is going with load e bfg and complaining about how gutless their trucks are.
M Blake Jr I guess you’re ok with contending with more sidewall failures than other Taco drivers?
I’m considering something similar for my Jeep.
Your wrong! A bigger tire size will increase the speed not lower it. The computer only understand rotations so on the bigger tire size the length is 4-5% longer on each +1Radial . Since it knows on standard tested size on X rotation u got Y speed, if the dumb driver mount +2R tire, computer will know and display 60 km/h because it knows it got lets say 2k rotations but on the 2k rotation add the length difference and u get 65-67 km/h. How do i know? I've tested and all time is the same, you gain speed and grip with bigger tire size (performance).
We said that installing a taller tire will cause the speedometer to read slower than your actual speed, which is the same as what you're saying, that your actual speed will go higher than the speedo when you mount a taller tire. We're saying the same thing.