What's the difference between AWD and 4WD? I was handed the keys to the brand new BMW M5, which can actually switch between 4WD and 2WD! Nothing all that impressive for any truck drivers out there, ...

Both cars have 530 hp, are all-wheel drive ... into the double-clutch gearbox, there's a transfer case in which, instead of a center differential, a center wet multi-plate clutch system lies.