Hey guys,

After years of testing and compiling data, I finally condensed everything I have learned down into one article on How to PROPERLY select and size TIRES for PERFORMANCE.


This article disproves a lot of common misconceptions (actually, almost every aspect of the tire from the UTQG and temperature to the labeled width of the tire) and challenges the typical thought process of how people look for new tires and gives a better alternative that will make sizing wheels and tires much easier in the future with less trial and error. The information here applies both for street cars as well as dedicated track cars.


"The most important part of your car is not the engine, suspension, or brakes. It’s the TIRES!!! This is because your car can only perform as well as the capability of its tires. I’m often asked which tire is best and what size to buy. In this article I discuss my methods for choosing and properly sizing the right tires. I’m not into the “hella-flush” or “stance” scenes so this article is focused towards those who care about the PERFORMANCE of their car, whether on the street or on the track."

How to PROPERLY select and size TIRES for PERFORMANCE > MotoIQ - Automotive Tech, Project Cars, Performance & Motorsports




Enjoy

 

Interesting read, thanks for posting!

 

I love tirerack as much as the next person... but did they sponsor that article?

The article is a great summary of the process and factors people need to consider when shopping. But it doesn't really back anything up with actual testing or conclusive data. This isn't bad, but it does make bold claims about certain tire stats being completely useless, while not provide any legitimate offering or other data to go off of.

For instance, I agree UTQG is a horribly unreliable source for tread-life, but it's still more reliable than nothing. And let's not forget that many competitions require you to use a tire of a certain UTQG rating to compete. That, in and of itself, makes that number a hugely important factor to some people shopping for performance tires.

In the end, it's hard to make a summary post that covers everything across the board. This all really boils down to a lot of vehicle specific applications where people need to turn to forums to find out what actually works. Having a larger tire on a heavier car is good, but will it clear the fenders? What size and offset wheel needs to be used with that larger tire in order to fit without having to sacrifice alignment setting?

Those are the real questions. But close to impossible to answer in a generic article.

 

No Tire Rack did not sponsor the article. However they are the only source that I have found that uses a standard process for measuring tires of various makes and models (everything they sell).

The article was mostly pointing out the vagueness of many tire 'specs' that many hold to be fact, which is rarely the case. As far as testing or conclusive data, the treadwidth to wheel width ratio guideline that was recommended was based off of testing hundreds of cars/tires/setups.

0.02

 

agreed. when shopping for a daily tire some people would be sorely disappointed with the wear on their "cool looking" NT-01s LOL.
and i'd be put into another class if i went softer than my 200TW tire. very important tool for those reasons. but not to be confused with using it as an absolute to compare which tire performs better.

i think it's good to point out tire issues. paying attention to tread/section widths and what size wheel they are measured on is important, but not everyone realizes everything differs a bit depending on their wheel width. it's also important for people to understand how arbitrary UTCQ ratings are.
even with all this, it still varies on usage. for instance Autox guys use tires WAY too wide for their wheels, IMO. ultimate grip outweighs responsiveness for them. i do road courses so i can't have that soft and squishy of a sidewall.
but, at least understanding all the info you posted can help someone make more of an educated decision other than "what's the widest tire i can fit on my wheel?".

 

I'm not familiar with AutoX. Do the people who run those wide tires on narrow wheels have a wheel width rule limit?

 

i believe certain classes are limited to WHEEL width only. then they stuff the fattest tire they can. 275 on an 8.5" wheel? no problem LOL. i may be exaggerating, but they do some crazy stuff. it must work because they all do it. nothing wrong with loopholes, IMO.

 

autocross is stupid. Article is OK. Brings up good points on tread width. I'll also agree you want your rim width over your tread width about .5 inches, no less. A SLIGHT stretch of the sidewall will indeed increase response, but more importantly, preload a sidewall and prevent the contact patch from folding, leading to a lower static camber requirement. Downside is that it could theoretically restrict the total slip angle range, potentially reducing total ultimate traction, but that's real iffy and depends on tire construction. On something like an NT-01 that thrives on very large slip angles, it could make a difference. On something like the Maaxis tire or pretty much any other street tire, it won't be a hindrance. This is something that would require testing.

 

i agree. i run 255s on a 9.5 wheel and all i hear is "why don't you toss some 275s on their, bro?". i use R-S3s which have a softer sidewall, so that would be a bad idea.
i just ordered some RE71Rs so we'll see how those do.
i've researched what the Cyber Evo, etc all used and, even in pictures, you can see stretch to their tires. i figure if they say it's good, Robispec says it's good, and other drivers i talk to say it's good, then it must be because they all know a hell of a lot more about it than i do LOL. my lap times are pretty danged decent too, so it must be pretty decent.

 

275's belong at least a 10" wheel. I think I read in another thread that the consensus was 10.5's were ideal..

 

Sounds right. With all the wheels I've run, I seem to like
9 = 245
9.5 = 255
10 = 265
10.5 = 275
Some tires run wider than others, but those have been my favorite sizes.

 

We're close, but you like more stretch than I do.
8 = 235 (OEM Evo VIII & IX)
8.5 = 245 (OEM Evo X)
9 = 255
9.5 = 265 (my car now)
10 = 275
10.5 = 285

Evo X has so much more fender room than the VIII/IX. We can pull off a 265/35-18 Pilot Super Sport on a 9.5 +22 wheel without fender rolling. Great grip and steering feel for a mild bolt on car that is 100hp beyond stock.

Most all of that article is common sense that a performance car guy better know in his sleep.

 

Depends on the tire. For example, the 255 R-S3 has a 10.2" tread width, measured on a 9" wheel. The sidewall was nice and flat on my 9.5.
I haven't taken a good look at my Bridgestones, yet. They didn't have a 265 for a 17" wheel anyway.

 

Not sponsored far as I know.