I've been a huge fan of Michelin PSS tires and exclusively bought them for the Mustang over the last four years. So how did I end up here? This year, I was hugely interested in trying an "R-comp" tire. I had my eyes set on Bridgestone Potenza RE-71R's for two simple reasons: price and reputation. Although not a true "R-comp" tire on paper, it performs like one by the account of every single test and review I've read (down to wear rates...). They seem like they're easily the most affordable (from a big brand) R-comp tire and combine that with a reputation for having tons of grip, it was an easy top contender. I had my concerns, though. For one, I'm told and have read that they are an autox tire, not really designed for high speed, pressure, and temps associated with open track. For another, the Mustang is a heavy car (as far as track cars are concerned) being roughly 3,800 lb. (including driver), which will amplify the unwanted open track load...
I'm finishing up a comparison post (link to introduction: Intro: Focus RS vs Golf R vs WRX STI vs Evo X ) and, throughout the post, I realized that I have to go off topic a lot to talk about how each type of differential changes the way the car drives. As a result, I thought I'd write a separate post to go into more detail before I post the comparison to keep it more focused on the cars and avoid veering off topic too much. By saying "Limited Slip Differentials" in the title, I am including torque vectoring diffs because, although current conventional terminology treats them differently, a torque vectoring differential is, in essence, a very sophisticated limited slip diff (LSD) that can be manipulated to actively help the car handle better. And while none of the cars in the comparison use open (without help from the brakes) or non-gear mechanical LSD’s, I’ll briefly discuss them so that the post is more inclusive. I’ll only focus on using power to help the...







