Zeebone

Ive heard that the wider the tires, the better when autocrossing. My only problem with that is what if you run a wide tire and its rubbing alot. Wouldnt that slow you down quite a bit? dunno.gif

03-accent-03

That's more or less correct.

Rolling fenders eliminates/eases tire rubbing.

faithofadragon

I'm running 225/50r15 no rubbing

JonGTR

I have khumo 225/17's and didn't feel the need for a wider tire. They gripped like crazy. The worst part was the body roll, and then just needing more torque out of the corners.

Stocker

Boy talk about an endless debate. The short version is: shorter sidewalls, softer compounds, and wider widths are often a c-c-c-combo you will find when people talk about (only) wider tires. All three combine to make better grip, kind of, depending on the tire, its inflation pressure, and the track conditions. This is an unanswerable question for the average joe with less than "Department of _____" level budgets to blow on testing. But if you want to go a little further down the road, Google, as always, hooks us up

From the EVO community, the same question
http://community.evo.co.uk/forums/thread.c...&startRow=0

links from the thread:
air pressure/contact patch/contact patch pressure, with actual tire manufacturer data:
http://www.performancesimulations.com/fact...ion-tires-1.htm
the "yeah, but" objections:
http://www.carbibles.com/tyre_bible_pg3.html

187sks

I don't, but would if I was truly serious.

More contact patch = better. So for grip alone wider, taller, and lower pressure can all add to contact patch. Lower pressure is only good on a tire designed for it, it totally screws you on a regular tire generally.

Wide tires without a proper suspension setup to allow for the outside tires to have maximum contact at maximum cornering force will not yield much improvement.