Re: snow and BMW
Next time you see a 3-series (don't key it!) look how far forward the front wheels are, they are almost at the front corners, meaning that most of the engine mass is behind the front wheels, and the gearbox is about a third of the way back to the rear wheels.
Without getting too technical, some of the mass of both those (heavy) components acts on the rear wheels, add a rear diff, battery, fuel tank, passengers etc etc and you have your answer.
If you could see through the body work of a Z4, it's almost mid-engined, with engine and passenger compartment sitting between front and rear wheels (like a Boxter but the other way around)
In a transverse engined-FWD car, the engine and gearbox sit pretty much directly over the front wheels and exert less of their mass over the rear wheels. This makes them grip/steer better in conditions where you need to exert more force on the drive surface (be it ice or snow)
The front wheels will be further back from the front of the car to allow the drive-shafts to do their job without being significantly further forward than the inner CV joint (very complex dynamic-geometry at play here)
There are a few longitudinally engined FWD cars, such as the B5 Passat and (I think) Audi A4, so their gearbox's are usually part-way back into the vehicle, thus distributing a little more of the mass to the rear wheels.
Hope this helps.
Once Loved: 156 2.4JTD SP3
Last edited by Ricer; 07-02-09 at 08:17.