Im about to order some tires for a new set of wheels. 18x8.5 fronts, 18x9.5 rears. I plan to do some track days, and lots of back road shenanigans.

I remember reading somewhere that using a slightly narrower tire with a little bit of stretch actually improves turn-in/handling. If this is true, does it mostly apply to the fronts only? or rear also?

Im debating on running 255 vs 265 in the rear on the 9.5 width. what does everyone recommend?

 

Anyone?

 

While a slight stretch may enhance turn in a bit, you could be sacrificing overall grip with less width. With such a small difference in the widths you're looking at, you may also want to look at the specs of the specific tire. A 265 may have a tread width of 9" on one, and 10" on another.

 

Maybe this is the article you were thinking of, for running a slightly smaller tire width than wheel width. But like AE Racer said, they also mention to check the tread width and not use the tire width 245, 265 ect).

https://motoiq.com/how-to-properly-s...r-performance/

 

I personally prefer the slightly stretched tire. It makes the car more predictable and stable when it does step out. Right now I’m running 255s on a 10” wide wheel and it is very controllable.
Previously I ran 275s on a 9.5” wheel and I would experience snap oversteer where there was no correcting it once it let go.

 

Excellent info everyone, thank you!

Im leaning toward Direzza ziii’s, so I need to research how wide they actually run.

So everyone’s saying that it does affect it slightly. Would you say it affects it equally front to rear or more at one end?

Meaning, running slightly stretched front and rear vs just rear, or just front.

 

we have found on the race track, a little stretch helps.

we tried a 225/50/15 on a 15x8 wheel, and then a 205/50/15 on a 15x8 and then 15x9

lap times with the 225/15x8 were about the same as the 205/15x9, and we were a couple tenths off of the lap record