Forum Discussion

ShinerBock's avatar
ShinerBock
Explorer
Oct 20, 2020

Why diesels are most efficient around 1,800 rpm

Finally got more of an answer to why all diesels are most efficient around 1,800 rpm. In comparison to what I thought, it has more to do with how diesel burns than other things like compression ratio...
Tow Vehicles
Cummins12V98's avatar
Cummins12V98
Explorer III
Oct 22, 2020
"When towing, whatever gear keeps engine rpm between 1,800 and 2,000 rpm will give the best fuel mileage and power because that is the rpm window where the Cummins 6.7-liter makes peak torque.

I tow at 60 with rpm's about 1,750. Just right! That's with 4.10's. At 70 I am about 2,000.

With my last DRW I had 3.42's. I would tow in 5th at same rpm's as above, just right!

About Travel Trailer Group

44,030 PostsLatest Activity: Feb 06, 2025