ecm tune egr dpf intact

[Lead_sled]

I’m not trying to hijack the thread, but reading on this 1500 rpm deal. My truck runs around 68 mph at 1500 rpm in 10th gear. I’m running 11R22.5 and from online calculations, I have around 3.73 rear gears. So, anything below 68 mph, you’re saying I should downshift to 9th to preserve the engine?

I usually shift out unloaded around 1500 rpm. And usually shift out around 1700 rpm loaded.

The industry I haul for, I’m either at 36k unloaded or 78k-80k loaded. Nothing in between.


On a different note, I used to work for a large oilfield service company. All of their trucks were 350hp Cummins. Don’t know which engine. But rear gears were like 4.63. We would drive down the highway at 63 mph turn 1800-1850 rpms. Pulling 90k. Only got like 3 mpg