– Detroit, Michigan

Don’t get me wrong, I’m sure the new M5 will be absolutely astonishing once we finally get a chance to slip behind the wheel. Yet having spent two long stints at the helm of the BMW M550i, both in California and the Midwest, I can’t help but argue this is about as much “fast” as most people need in their 5 Series. I know, I know, I’m being a killjoy – trust me, I still am itching to get a crack at that 600-horsepower M5. The truth is, though, that the M550i is tremendously capable and already delivers more performance than can be sensibly exercised on public roads.

Pros

Oh, it’s fast. Yes, it’s quicker to 60 mph from a stop than the old M5 (by as much as half a second, depending on transmission), but that really doesn’t tell the whole story about this car’s acceleration. The biturbocharged V8 has a cavernous reserve of torque, and it’s all dished up near instantly thanks to the twin-scroll turbos’ quick wake-up times and the promptness with which the automatic transmission downshifts. It’s the sort of car that makes one go, “Wait, how fast?” Never do I ever wonder if I’ve got enough oomph to blitz past a slower motorist or beat other cars down an on-ramp. Just point, accelerate, and get there.

Can still play the part of a cruiser. On a long highway journey with American speed limits, rather than Autobahn ones, one may as well settle in and relax. The M550i does this superbly, offering up a composed ride over broken pavement while fending off wind noise...