"It pounces on corners, tracks flat through the apexes, and devours the straights with a burly snarl from the V-8. It laps up freeway kilometers at triple-digit speeds, the suspension digesting ripples and dips so thoroughly that the body remains almost inert. All the driver has to do is aim the 645 and it goes there. Fast." Sounds great, right? Absolutely, except for the fact that it isn't about this 640i. Keen BMW fans would probably be fast to note that this 640i doesn't even come with a V8. The above is fro m a review of a 645Ci that was published back in January 2004, 12 years ago. This new review , though, was.. let's be kind and say less flattering. As seems to be a pattern now for all BMW's, except the 2-series and M models, there's lots of disappointment. "Our car, equipped with BMW’s M Sport package, offered what seemed to be a slathering of faux sportiness." It only managed 0.86 g on Car and Driver's 300-ft...
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...







