I know lots of people that run different tire sizes on wheels with the same width (225f 205r for autox) and I know that some cars use wider wheels (matched with a wider tire) in the rear of the car...

While reading through SCC this month I noticed an interesting twist to the above scenarios. They were test driving a few EVOs and WRXs (both track and street) tuned by BOZZ Speed in Japan. One thing this tuner did was to run wider wheels in the front of the car and narrower wheels in the rear - but they would run the exact same size tires both front and rear. The reason for this is to get more grip in the front by changing the shape of the sidewall of the tire with the wider wheels and in the rear get a nice progressive breakaway/rotation with the narowwer wheels. This made perfect sense to me.

Has anybody thought about or tried this on an R? I imagine it would would perfect for the 205/50/15 Falkens on 7" wheels in the front and 6" wheels in the rear...

 

Does this not interest anybody else?

 

that would make for a very interesting combo...

 

Yeah, Japanese racers do some crazy things... such as varying tire width/rim width on FF cars.

I suppose if we have tons of money to burn, we could try many different setups that work well for a track or two. But, the reality is that you probably will not find the perfect combo on your first try and you'll be stuck with some odd-ball tire/rim sizes that do more harm than good. Worst of all, the oddball setup will completely throw you off with different tire responses/predictability. It's hard enough to mix and match different brand tires using same size (two bridgestone 205/50/15s w/ pirelli 205/50/15s), so I wouldn't try it... unless I have a lot of money and time.

 

it does interest me but I know I don't have the cash to play...