At what point are you lugging a diesel?

[Jetronic]

Originally Posted By: mjoekingz28


I also consider torque to be different at different parts of the band. It seems, to me at least, that 1000lb-ft at 1000rpms will be different than 1000lb-ft at 4000rpm.





horsepower generated will be 4 times higher at 4000 rpm, that's the difference!

 

[Jarlaxle]

Put it in drive and don't worry...the transmission won't let it lug.

 

[columnshift]

Different engines lug at different speeds. There's a trend in Class 8 vehicles called downspeeding - towing at slower and slower engine speeds. It requires the engine and entire powertrain be engineered for it as it's carried further and further.

An engine like a Cummins 12v apparently doesn't like even 1600rpm or so and can be damaged by inadequate oil flow, but for what i've heard the newer Fords run very well at slow speeds. I would assume anything programmed from the factory in an automatic transmission though is never a problem, you'd need a manual to lug it.

There's also no point in lugging it, lower rpm is not necessarily more efficient, specific fuel consumption drops to a point usually where the torque drops off then increases below that point making it a less efficient way of moving a load.