Horsepower is the power that the engine develops, at a given RPM it is the only number that will tell you how fast the car will accelerate or top out at.

There are two components to horsepower, RPM and torque. Torque is one of the two factors that determine how much power an engine develops.

If you know torque and RPM, you can find horsepower, and vice versa.

The formula is: Horsepower = (Torque x RPM) /5250

For example, my C280 puts out 199 ft/lbs of torque at 3750 rpms. From the formula, we can calculate that the horsepower at this rpm is 142 hp.

Also note from the formula that for every engine in the world, torque and horsepower are always equal at 5250 rpms.

If one car puts out 400 ft/lbs of torque at 2000 rpms and another puts out 200ft/lbs of torque at 4000 rpms, there is the same exact power being geneated. Both engines will be identical in performance.

Don't let anyone tell you that their car is faster simply because it has more torque, it may be faster but that is only if has more average horsepower throughout the engine's useful range. If torque was the only thing that moved a car, then you wold accelerate harder at 3,000-4,000 rpms than at higher rpms, and we know that this is not the case.

__________________
Ali Al-Chalabi

2001 CLK55
1999 Dodge Ram 2500 Cummins Diesel
2002 Harley-Davidson Fatboy
Merlin Extralight w/ Campy Record