Pardon me if this has been covered before but just glanced at the online brochure and see the S63 has 603 hp, 664 torque and 0-60 time of 3.4 sec. The S65 has 621 hp, 738 torque and 4.2 seconds 0-60. Why is the more powerful car slower? It's can't weigh that much more. Gearing? At more than $80,000 extra I'd think it would be quicker.

All wheel drive on the 63 and not on the 65.

OK thanks.