Originally Posted by Detlev Bronk
As for xdrive, the extra weight is something I'm concerned about, which is partly why I'm reluctant to go for other options that add weight. But if I'm not mistaken, the xdrive actually improves 0-60 time performance.
You may be right, but I would be very surprised, as mass (power-to-weight ratio) is the leading obstacle to performance. Perhaps the test should be run with non-OE tires which will have improved grip if rear wheelspin is the culprit for a WOT launch. I have long questioned the value of all wheel drive systems for on road use. On flat winter surfaces, dedicated winter tires are excellent and have proven themselves over many years. Going uphill, weight transfer requires more traction at the rear as the front wheels unload. Going downhill, the traction needed at the front is for braking/turning, which is a function of tires, as you already have gravity helping with motion. So, why add 100lbs or so over understeering weight over the front wheels of a rear wheel drive car 24/7/365?? Especially one already working to cope with a 6 cylinder engine in a M235? Especially one that costs more to buy and maintain and drinks more gas (due to increased mass)? For the sake of the incredibly rare instance where a front tire will find traction when at standstill when the rear tires won't? Not worth it.
Until I get my BMW, I've been driving a rear wheel drive 09 MB C300 6 speed stick (any buyers????) and using Blizzaks for Michigan winters. No problems. I've had C Class 4MATIC loaners, and they just don't feel the same....and not for the better!