keeperlit

REV App Turns iPhone Into Performance Driving and OBDII Diagnostics Tool Obviously the power and torque are not always the same, it depends on engine speed, that's why the formula listed contains rpm as a parameter. I only listed these to show that if you know the engine speed, then power and torque are just two different ways of stating the same thing. But you don't need to know engine speed to calculate power/torque output, its only one way to do it. By definition power can be calculated if you can measure the rate at which work is being performed. Therefore if you know the acceleration from GPS and the mass of the car, you can calculate power. Anyway, this is not the only app available that does this type of thing, PocketDyno is a free iPhone app that calculates power output. I've tried it, and it works great. So if you are worried about getting ripped off, or didn't do well in GCSE physics, then try this one first.

REV App Turns iPhone Into Performance Driving and OBDII Diagnostics Tool "it's torque which gives acceleration" by implication bhp doesn't contribute? Eh? Horsepower = Torque x rpm / 5252 so Torque = Horsepower x 5252 / rpm As power is a measure of the rate of doing work, if you know the weight of the car, and how fast it is moving, you can calculate how much power/torque is being used. Force = Mass x Acceleration That's not fiction, that's physics.