Horsepower is horsepower?
If that theory is true (in real circumstances), then a 385hp 6.7L Cummins diesel shouldn't spank a 381hp Toyota Tundra when both are tested 0-60 towing a 5740# boat. But it did. Must be the adva...
Forum Discussion
Sinterior wrote:rightyouareken wrote:
Not only that, but horsepower is mathematically calculated from torque and rpm. The calculation is:
Horsepower = (torque * rpm) / 5252
If that's true, then Ford, GM and Ram are fudging the figures re HP and torque if you look at he numbers.
Or, am I missing something here?
You are missing something then, because that is how horsepower is calculated. If you look at a dyno graph, HP = Torque at 5252 rpm.
As several have stated on here, there are a lot of variables when it comes to this. Altitude makes a big difference, turbo motors lose about 3% of their HP for every 1000ft, where as N/A motors lose about 7% all due to the air density.
Gearing and tires have a lot to do with acceleration, same with weight.
For the most part, if you graph HP and Torque, the car with the most area under both of the curves typically will win in short sprints. For longer, higher speed runs, the car with the most HP typically will come out on top.
Remember, manufactures state engine dyno numbers, not chasis dyno numbers. So 400hp on an engine dyno (without transmission, drive line, tires, etc.) would equal about 320-340hp on a chasis dyno which measures HP at the wheels. Some vehicles have a lot more drivetrain loss then others.
