what would the time difference be between a driver running on street tires and the same driver running the same car on slicks? A ballpark figure is all I'm looking for. Thanks, Tony

 

I am told 2-3 seconds.

 

these estimates would only pertain if a limiting factor was indeed the tires to begin with

 

Depends on which street tires you're comparing R-compounds to, and whether you're comparing to SCCA stock-class-legal DOT R-compounds or true racing slicks.

The "top" autocross street tires (Azenis, MX, Neova) are not too far from the top DOT R-compounds (710, A3S05). 1-2 sec.

 

If you can push the R-compounds to their limit, 1-2 seconds depending on which tires you're talking about. Most people switch to R-comps long before they have exceeded the limits of their street tires and are simply using the R-comps as an aid for quicker times. However, if you want to be competitive and others in your class are on R-comps, you sometimes don't have a choice