As he said it depends. With my Azenis I usually get a season and a 1/2 with mine but that also includes driving to and from events on them. Probably sees about 10,000 miles and about 60 autocrosses. But I constantly keep a check on the tire tread depth and always put the ones with more tread on the fronts. Also depends on your camber, your driving style, amount of toe front and rear, and how heavy your car is.

My Hoosiers have only seen 3 events this year so they are practically brand new

Selling the Si so I can get cracking on a new car and maybe buy a tow vehicle and trailer. I have a 1991 Civic Si which has not lost an autocross since April That's 25 out of 27 autocrosses I believe it has won. I'm thinking about trying a 1992-1995 Civic Si next year.