The Definitive Torque vs. Horsepower post
Year after year, I keep seeing the same old debates about torque vs. horsepower. Everyone seems to have a general idea that we are referring to power, but most don't really understand the relationshi...
Forum Discussion
pnichols wrote:
Well ... I hate to throw water on any diesel-lovers parade, but a quick read of this just might help separate fact from fiction regarding why the equation for an engine's torque depends directly upon it's horsepower:
http://lainefamily.com/hp.htm
You may want to restate that statement!
Horsepower = speed (RPM) x torque (ft-lbs) / 5252
Seems to me the Equation states that HP is a product of speed and Torque. :B
There is a point that to get the RPM necessary for low torque engines to make the necessary HP, it will exceed the engines red line.
So you run taller than stock tires to improve fuel mileage, maybe final of 4.30 from the 4.56 of the differential, but you are only moving 11,500#. I pulled a two horse GN trailer (about 5,000#) about 250 miles home, and needed to constantly check the mirrors to be it was still there, Total GCVW about 12,500 to 13,000#.
This example is just that same rear gears, gearing needed to get necessary torque limited speed to 25 mph.
JIMNLIN wrote:
My '03 truck= 305 hp Cummins.
Buddys '04 truck= 305 HP Nissan
My '03 truck = 555 ft lbs Cummins.
Buddys '04 truck = 379 ft lbs Nissan.
Both trucks have 3.73 axles pulling the same 4800 lb 21' bass boat/200 Merc over the same roads to the same lakes for the same bass tournaments.
The Nissan drags down to 25 mph in low gear and won't accelerate on one long steep highway in the hills.
The Cummins keeps the 50 mph highway speed limit at 1900 RPM an can still accelerate in the same gear on the same hill.
It is true that you can't have one without the other. Given the choice (Oh yes I was given the choice :)), I would rather have higher torque than HP as as long as the difference is reasonable it is a much more relaxing driving experience.
