[Porsche-O-Phile]

I suspect a lot of the horsepower / torque on the base model is simply driven by marketing - enough to keep the reputation of "yes, it's a Mustang" alive but also making the prospective buyer wanting a little more ("hey, over here we have a Shelby model that's got more power...") All car manufacturers do this, I'm sure Ford is no different.

FWIW I had an '83 GT years ago. Loads of fun and probably weighed 1/2 to 2/3 what today's pigs do. And to be fair the Mustang is small compared to the new Camaro which by all rights should be a pickup truck. They've both gotten really, really fat and hulkish and bloated IMHO.