why is it that (usually) bhp of a diesel engine lower than petrol ones.?

Question

I Believe Diesel engine is more powerful than petrol .. then why is the difference ????

Answer 1

bhp = RPM * Torque / 5252

Diesels are made out of heavier, more durable parts than gasoline engines, so they are unable to operate at high RPMs. So although they may have a lot of torque, the horsepower rating tends to be "surprisingly" low.

Go to the following website for some more information: http://vettenet.org/torquehp.html

Answer 2

Horsepower is a function of torque and RPM. Diesels have a lower horsepower rating because they spin so much slower than a gas engine. Many gas engines can spin about twice as fast as a diesel. While a diesel has much greater torque than a gas engine, when you run it through the horsepower equation, it comes out as a low number because of the lower RPM's it runs. A decent torque number combined with a high RPM gives a gas engine a comparatively higher horsepower number.

Horsepower is determined by: (torque X RPM)/5252. Horsepower and torque are equal at 5252 RPM. Hope this helps.

Answer 3

All of these answers are right. Diesels may have less horsepower but there torque is through the roof. There is a big difference between torque and raw horsepower.

Answer 4

diesel has WAY more torque. Which is where the real power comes from. Check out www.howstuffworks.com then go to diesel engines. ITS GREAT.

Answer 5

Because you'll find more torque in a diesel engine. But don't get me wrong, they can pump out some nice HP numbers too.

Answer 6

It's true. But, that's with the engine at it's maximum output.
If you drive a gas engine at it's maximum output for more than a couple minutes, it's going to blowup.

Diesels have greater torque at lower engine speeds and can run that way ALL DAY.

Answer 7

They don't spin as fast, Hp is torque X RPM.