Question: smaller front vs rear tires?, what's the rationale? Options

[nine14cats]

Here's a question that for no particular reason I ask...other than I want to know! I'm sure this board has plenty of suspension guru's... (IMG:style_emoticons/default/biggrin.gif)

Question: What is the reason for a smaller size front tire/wheel than the rear? Particularly on race cars? On my street 911, or even race 911's, it's usually real big meats in the back and much smaller in the front, even with fiberglass fenders that can house larger tires up front. On my race only 911, I run the same size slicks all the way around, as do many 914's.

Most track cars seem to run bigger tires in the back, front engine, mid-engine, or rear engine.

Why?

I look forward to the education! (IMG:style_emoticons/default/tongue.gif)

Thanks,

Bill P.

P.S. We were sitting around last night wrenching on the race car and this came up....nobody had a decent answer... (IMG:style_emoticons/default/rolleyes.gif)

I like to believe the "track" width between the left and right tires makes a difference in traction. If you had 205's all around, but the rears are father apart than the fronts, you probably would have more rear traction. On my CRX, I have tried weird stuff like running 225's in the front, and 205's in the rear. It gave the car some ultimate steering response. But it also felt a bit sluggish when accelerating too.