I’m running a set of 275/335 Rival S tires for SCCA AS AutoX. I need a new set, and those are still available, but now there is a new listing for the 275/335 sizes in the Rival S 1.5. Last time I looked they didn’t have the wider sizes in the 1.5 version. Anyone know if there is any real difference? A bit cheaper for the 335 1.5s, but same price for the 275s.

Very interesting new option for the C6 Z06. I've also been running the Rival-S tires on my A-Street autocross car. Always wanted to options, such as the RE71-R, but Bridgestone still hasn't made a 335/30-18. Sounds like the new Rival-S 1.5 is trying to get the stiffer sidewall response that the RE71-R seems to enjoy. Will be looking for new tires later this year, hoping for good reviews of the 1.5 too.

Based on all of the other street classes, I expect the 1.5's to be quicker.

The 1.5s have a stiffer sidewall with the new construction. I think we have a choice now between the S and 1.5 but I imagine that is only while the non-1.5 is in stock then thats all that will be available just like they did with the smaller sizes that went to the 1.5 last year.

I'm not sure I'd want the stiffer sidewall, at least not in the rear, I like how the S puts power down. If anything the 1.5 up front and S in back, for now. I think once you go 1.5 all around you'll need to make some setup adjustments to account for the differences.

If I were running a non square rotatable setup, this is what I'd do.