F350 Super Duty vs 3500 Denali vs The Ike Pulling 30k lbs

rhagfo wrote:

4x4ord wrote:


The interesting thing about the Cummins vs Duramax is that the Duramax makes 445 Hp @ 2800 rpm vs the 400 hp of the Cummins. But as the Duramax pulls down it dramatically looses power. In fact if it were allowed to pull down all the way to 1600 rpm where it makes peak torque it would loose 167 hp. The Cummins on the other hand looses very little hp as the engine slows down. In fact the Cummins only looses 57 hp slowing from 2800 rpm down to 1800 rpm where it makes its peak torque. For this reason the Cummins doesn't need a 10 speed to compete with the Duramax. The Cummins will be putting out more power than the Duramax at rpms below 2250. Above 2250 the higher power of the Duramax starts to come into play.
The Ram's ability to produce power at a lower rpm might allow it to get a little better fuel economy under certain conditions.

Well once again I think it has more to do with torque than hp, the Cummins has a 45 hp DISADVANTAGE to the Duramax, BUT a 90 lb ft torque ADVANTAGE to the Duramax.

4x4ord wrote:


Ford did dominate the uphill run. The difference in time indicates a 46 horsepower advantage that the Ford has which is a little more than the difference in advertised power ratings.

Well while the Ford does have a 46 hp advantage, it also has a 140 Lb Ft torque advantage.

Towing heavy is more about torque than HP!

You are right. The peak torque defines the power level at the lower end of the power band. The peak HP defines the power level at the upper end of the power band. With a 10 speed transmission the Duramax will do much better because it can run closer to the rpm where it makes peak HP. A higher torque and lower HP engine such as the Cummins is not as concerned about its rpm. If you were to compare the power or torque curves of the Cummins and Duramax you would find that below about 2250 rpm the Cummins makes more hp where as above about 2250 rpm the Duramax makes more power. And, so, at about 2250 rpm the two engines make identical HP.


Edit: Just to state it another way you can talk HP or torque it makes no difference. In other words, above 2250 rpm the Duramax makes more torque than the Cummins and below about 2250 rpm the Cummins makes more torque than the Duramax does.