Can I mount a set of 295 / 35 - 20s in place of the stock 285 / 35 - 20s without affecting the traction control or anti-lock braking? (For my sig car) Tire guy is thinking it might trigger an ABS issue since it is a bit taller than stock.

I got shipped a set of Michelin Pilot Sports (wrong size) that are supposed to be a bit stickier in the cold than the stock Goodyears.

 

Yeah, they won't affect traction control or ABS. Those are typically based off wheel rotational speed sensors...As long as they spin are are not a couple inches of diameter different all is good. I think the dude might think your difference in diameter may make the computer think the fronts are moving at a different rate than the rears. Those systems are more concerned with side to side differences as to keep the car straight. Even so the difference is very small and I wouldn't be afraid to do it. I have an extra set of GT wheels 235mm wide 18inch with stock GT pirelli zero neros (or what ever) for my '11 gt500 that I planned on using (I haven't yet).

 

I ordered a set of Pirelli P Zero's used off ebay to try them and these showed up...good for me. The Michelins are the same rating as the Pirelli's and they are dang near new. The Pirelli's were very worn, but so cheap compared to new I wanted to try them.

Here is what I got for 170 bucks. Two Michelin Pilot Sports in 295/35/20 size.

 

Seems like a pretty good deal! See when I bought my car I was worried about the cost of tires killing me. Since the car has tons of power and I had read "a lack of grip"...coupled with my driving style... Sounds like you may be thinking similarly. I see you have a busa too! I have a zx10R, our bikes eat up tires so If you've ever shopped for tires for that thing you'll know different tires act differently (seems like with bikes it is easy to tell the difference quickly). You'll have to tell us how these work for you.

 

The Michelin's did not cause any issues with the anti lock or traction control. They do still suffer from poor traction performance in the cold weather. I will cut them some slack today, since it was 16 degrees on the drive home after having them mounted.

As for the Busa, it eats tires....I took it to Barber three times this year!