A torque curve is simply the graphical representation of the torque vs. RPM relationship, i.e. how much torque is available at a given RPM. Large and forced induction engines typically have more torque available at lower RPM's and maintain it through the engine's range, resulting in a "flatter" torque curve. Smaller, high-reving, multi-valve engines achieve high horsepower numbers for their size but torque remains low and is acquired in a gradual, more linear fashion (think 45 degree angle vs. flat line). Your NA Lancer curve is probably very similar to that of other 16-valve 2.0 liters: Mazda Protege, Honda RSX, VW Jetta. Note that the RSX S has one more ft. lb. of torque than the base RSX, but it's only available at a lofty 6000 RPM rather than 4000 for the base model. In contrast, the turbocharged Audi/VW 1.8 liter engine in my Passat makes about 155 ft. lb. (max) of torque available from 1,800 - 4,500 RPM, as I recall. According to Mitsubishi's site, all US Lancers develop 130 ft. lbs. at 4250RPM, so I'd guess that at around 3000 RPM it's making less than 100 ft. lbs., roughly what small cars of twenty-five years ago made without 16-valve heads. What all this means is that when you floor the gas pedal at a given RPM, the torque (power) is either available to press you into your seat, or you have to watch the tach needle climb before you feel anything (or downshift)