Those that have tuned or programmed

4x4ord wrote:
Could be the more sustainable torque/power numbers are those that are made for medium duty applications ... so for the 6.7 Cummins and Powerstroke the number is around 750/330 torque/power as compared to the pick up truck ratings.


Edit: our Peterbilt doesn’t provide enough water cooling to prevent defueling on a hot day and the 15 litre Cat makes 550 crankshaft hp .The comparatively small rad on my pick up is going to have its work cut out for it trying to deal with 475 HP.

The 6.7L cummins gets up to 360hp/800lb-ft in medium duty/bus/RV application and 550 hp/1,250 lb-ft in marine applications. Marine engine can sustain that much due to using sea water to cool the engine and they have lower emission requirements. The engine is mostly identical to the on road 6.7l aside from not having an EGR, larger injectors, and a larger wastegated turbo. The lower numbers on the medium duty/bus/rv applications are mainly due to different emissions standards.

When I tow in my 475hp at the wheels tune, I very seldom even need to use the 548 crank hp unless I am passing. I am generally at around 1,800 rpm most of the time. It is the 1,100 lb-ft at the wheels at 1,800 rpm that I use more often. Even in the Texas heat, my temps are always where they should be. If they ever start to get too hot then I will lower it down to the 425 hp at the wheels tune or the 400 hp at the wheels tune.

Difference between QSB 6.7L and ISB 6.7L

Q stands for off highway engine and I stands for on highway.