As has been stated, it only matters how the car feels behind the wheel of it. How do you really know what 12 hp or 5 hp feels like if it's been unchanged, only re-defined? It's all perception and marketing.

I've seen with my own eyes a 2004 Accord EX V6 coupe with the 6 speed leave a 2003 supercharged Pontiac Grand Prix GTP behind in the 1/4. Both cars bone stock, no modifications. Both cars are rated at 240 hp.

What manufacturers must do, in my opinion, is go by the DIN (Deutsche Industrierten Normen, or German Industry Standard). The German DIN is, basically, your net hp. "At the wheels" as people like to say. It's the true numerical output of hp and Tq after everything has been taken into consideration (accessory motors, engine and vehicle weight, drivetrain loss, aerodynamic forces). The numbers might be low, but at least they are accurate and consistant.

Or, we could go back to the old SAE gross (pre-1973)..... then all of our 4 cylinder cars would be making 350 horsepower