Forum Discussion

bluwtr49's avatar
bluwtr49
Explorer II
Jun 06, 2015

Torque vs. HP

Just stumbled across and interesting article that folks might be interested in seeing.

Torque vs. HP
  • Where gobs of torque seem to make a big difference is when starting from a standing stop on a steep grade. A big diesel has peak torque around 1300 rpm and peak HP at 2100. A gasser may be closer to 3000 for peak torque and 5000 for max HP.
  • Torque (at the wheel): Determines if you can get up the hill.
    HP: Determines how fast you get up the hill.

    Key point: Torque measured at the wheel. A gas engine with half the torque running twice the RPM thru a lower gear will go just as fast as the diesel. The question is does the gas powered truck have the gearing to do that.
  • holstein13 wrote:
    Here's the bottom line: horsepower = rpm x torque / 5252. Essentially, if you have low torque, you'll need to increase your RPMs to get higher horsepower. Think of a Formula 1 car with low torque revving up to 15,000 RPMs. Some have gone to 20,000 RPMs.

    I think Diesel folks like having more torque because the engine doesn't have to turn as fast to produce the same horsepower. Less RPMs equals less heat, noise, and friction. But the easiest way to increase horsepower is to increase RPMs.

    But the only time you are near your maximum horsepower is when you are close to redline. Usually during acceleration or climbing up a mountain.


    Very well said
  • Here's the bottom line: horsepower = rpm x torque / 5252. Essentially, if you have low torque, you'll need to increase your RPMs to get higher horsepower. Think of a Formula 1 car with low torque revving up to 15,000 RPMs. Some have gone to 20,000 RPMs.

    I think Diesel folks like having more torque because the engine doesn't have to turn as fast to produce the same horsepower. Less RPMs equals less heat, noise, and friction. But the easiest way to increase horsepower is to increase RPMs.

    But the only time you are near your maximum horsepower is when you are close to redline. Usually during acceleration or climbing up a mountain.