Hi,

Stupid question, but are the official HP ratings of our cars taken at the flywheel or the rear wheels?

 

At the flywheel; with the engine exactly as it would be installed in the chassis, with water pump, alternator, stock exhaust, stock air intake, all "accessories" (that means meissions control devices, not A/C and power windows and such) operating, pump gas meeting the minimum owner's manual specs, unmodified production-line fuel and timing curves, etc. In short, an attempt to replicate what a customer would actually receive when buying a new car.

Very different from the "ratings" of the 60s, which were highly flogged dyno mules with no accessories of any kind, specialized dyno exhaust and air intakes, race fuel, careful tuning, etc.