A couple of weeks ago, I posted my first impressions of Michelin's PSS vs Firestone Firehawk Indy 500 tires. I've run PSS's for several years on the Boss, but I'm trying the Indy 500's for the first time. In short, I was worried about the narrower tires (I was running 285/35/18 PSS but could only find the Indy 500 in 275/35/18) and tread squirm, but I was happy with them up to that point just driving on the street. I had the chance to drive on them for three track days now. So what were they like? After my first session, they made an impression that basically persisted for the rest of track sessions on them. Phenomenal, unmatched value. Now, if value is something that stands out above all else, it typically means the compromise between qualities you want and those you don't is less than ideal, but the value is attractive. This is no different. I'll start with the bad, which really boil down to two: ultimate grip and grip longevity. Grip is noticeably l
BMW M2 equipped with an eLSD - BMW © A few weeks ago, I posted about traditional clutch-type limited slip diffs (LSD's) and how they work. You can read about those in the previous post: How Limited Slip Diffs Make You Faster on Track . But as you might know or have learned from reading the article, they aren't without their faults, which means engineers are always working to get around those limitations. You may not be surprised to learn that something like the Ferrari 488 GTB doesn't use a traditional limited slip diff, but it's not limited to super cars, far from it. Cars like the Golf GTI, the Civic Type R, various Mustangs, Corvettes, and BMW M cars, and even the Lexus RC F and GS F, all avoid a traditional limited slip diff in favour of one of these technologies. To keep things simple, I'll focus on two wheel drive vehicles. The vast (vast) majority of principles apply to all and 4 wheel drive vehicles, but there are some subtle differences that I'll