Privacy Policy

                                       DRIVING TIPS

Torque versus Power

In the simplest terms, torque is the twisting force the engine applies to the crankshaft and then on to the transmission.

Power, by contrast, is measured as the torque times the rotational speed. In imperial measures, one horsepower is equal to 550 foot-pounds (of torque) per second. Two engines can produce the same power but have very different torque ratings for the following simple reason:

One horsepower can be produced by moving one pound 550 feet OR by moving 550 pounds one foot, provided that either function is achieved in one second.

The difference comes in the fact that the high-torque engine will be rotating slower than the low-torque engine at the same power output but it will be twisting the crankshaft a lot more vigorously.

In theory, different gear ratios - most commonly four or five in cars' gearboxes - should mask different torque characteristics by altering engine speed to suit but the reality is that engines which produce high torque figures at low revolutions respond much more readily in give and take driving.

The practical advantages come in the form of reduced gear changing, lower engine revs and wear and, invariably, lower fuel consumption in all conditions other than constant speed driving.

For Mr Average, torque is therefore more important than horsepower, unless you spend your life racing around at high revs.


Back to Tips

Site design and layout copyright 2002, Modernracer.com  All rights reserved
All images and trademarks are the property of their respective owners. No part of this website may be reproduced without the explicit permission of the owner of this site.