Rear biased weight distribution when loaded - A rear-wheel-drive car's centre of gravity is shifted rearward when heavily loaded with passengers or cargo, which may cause unpredictable handling behavior at the hands of an inexperienced driver [REF].
The possibility of a slight loss in the mechanical efficiency of the drivetrain (approximately 17% coastdown losses between engine flywheel and road wheels compared to 15% for front-wheel drive - however these losses are highly dependent on the individual transmission).