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ib516's avatar
ib516
Explorer II
Aug 21, 2013

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 advantage the turbo offers the Cummins, since the test was conducted in Colorado. The Cummins took 15 or 16 seconds, and the Tundra took 19+.

I saw the comparison on "The fast lane truck" YouTube channel. They also test the new 385hp/850tq Cummins towing a big load up to the Eisenhower tunnel, but so far, they have nothing to compare it to. Cool channel though.

Tundra w/boat 0-60

Ram 3500 w/boat

Tuned Duramax w/aftermarket intake & exhaust w/boat

2013 Ram 3500 with 17000# trailer up Eisenhower tunnel grade
Video

360 Replies

  • Torque and HP are related and can never exist at any non-zero RPM without the other. Ultimately the diesel twists the shafts attached to the tires with more force longer. In this case it is enoungh to make up for the other differences by far (weight and aero).

    http://www.epi-eng.com/piston_engine_technology/power_and_torque.htm
  • Not only that, but horsepower is mathematically calculated from torque and rpm. The calculation is:

    Horsepower = (torque * rpm) / 5252
  • wnjj's avatar
    wnjj
    Explorer II
    The HP rating is only a peak rating. The amount of HP you get to the ground from a dead stop and through all the gears is what matters. It's is why high torque motors pull hard. They produce relatively high HP throughout their operating RPM range.

    It's all about actual delivered HP.
  • Actually, horsepower and torque vary across an engines rpm range. That is why both are charted on torque/horsepower curves. The advertised horsepower and torque are the peaks on the curve. In general, an engine with a flat curve will out perform an engine of the same horsepower/torque that has peaked curves. Diesels typically develop their max horsepower and torque at lower rpm than gasoline engines. That's what makes diesels better tow vehicles.
  • iawoody2 wrote:
    As a former drag racer hp is what gets you going, torque is what throws you across the line.



    I always heard it pretty much the other way round.

    "Torque makes you go. HP makes you go fast."



    In any case, the age old argument, with proponents of each side claiming the other is full of beans and blah blah blahhhh.
  • ib516 wrote:
    If that theory is true (in real circumstances),


    That theory is only true when....all other things are equal. And they are usually not. Especially when comparing different brands.
  • Horsepower is horsepower is something someone who doesn't understand what they are talking about says.

    Lots of other factors. Torque, gearing, transmission ratios, weight, aerodynamics, etc.
  • As a former drag racer hp is what gets you going, torque is what throws you across the line.
  • Horsepower is what a race car needs....Torque is what the truck that hauls the race car has!!!!
  • In the high altitude of Colorado the normally aspirated Toyota won't be making it's rated HP. The turbo charged Cummins will.
    There's more to "drag racing with trailers" than just HP. Torque, RPM, torque curve, gearing, etc. all come into play.