Cerowyn:
Jet_Jaguar:
I would guess the reason actually has to do with the emissions and economy regulations that were first imposed in the 1970’s, and technology playing catch-up. For example, the Corvette’s power output peaked in the early 70’s at around 425 hp, but by the early 80’s that had fallen to somewhere around 185 hp. But starting in the 80’s, technologies such as electronic fuel injection, dual overhead cams, variable timing, and such, improved efficiency to the point that engineers were able to claw back the power lost while still complying with regulations.
Minor nitpick: the Corvette’s LS engine (used in the more common models) is still pushrod and didn’t get variable valve timing until 2005. It’s also still only a two-valve design. The vaunted ZR-1 used a double overhead cam engine, but that was dropped with the sixth generation design; the new ZR1 uses a turbo-charged derivative of the base engine.
No Corvette engine has variable valve timing. The L92 truck engine used in the 2007+ Escalade, Hummer H2 and GMC Yukon does. The new ZR1 is supercharged, not turbo charged.
Are you saying they were fudged low or high? Cars like the Boss 429 were deliberately underrated for insurance purposes.
Let’s not forget that HP is simply mathematical calculation based upon torque and engine RPM. The formula looks like this:
HP = Torque x RPM divided by RPM