[MilzyZ34]

They just boost the number to sell cars. Nothing more. Throttle body, cam, valvesprings, heads, intakes, pistons, rods, ignition system, exhaust manifolds, etc are all the same. The tunes are not more aggressive in one than another. Tunes very year to year, but not vehicle to vehicle, atleast as far as horsepower goes. The exhaust may be a different configuration from one car to another, but the downpipes are all the same diameter, so they flow the same.