Ram Cummins Vs GM Duramax Ike Gauntlet

Groover wrote:
"I can guarantee you that the DPF's were getting hot enough to passively regen up that hill. Anytime you are at high load for periods like that will trigger a passive regen due to the DPF getting hot enough without the use of extra fuel."

Are you saying that a "passive regen" is an actual event to the engine or simply that due to running the engine so hard the filter got hot enough to self clean and no further action by the engine management system was necessary?

If they had followed this piece of advice " I am not too fond of pulling a load like that up a hill at 1,600 rpm and would rather be in the 1,800-2,200 rpm range to keep EGT's as low as possible." would that have killed the passive regen?

A passive regen occurs when the exhaust gets hot enough to ignite the ash in the DPF without any assistance from the engine such as injecting extra fuel. This is usually around 850F which can be achieved with constant half throttle and moderate boost. Diesels can easily get to this temp just towing a 10k on flat ground or just going up a hill unloaded. Most diesels are between 400F-700F when not towing an not going up steep grades so they do not get hot enough and need the engine to active regen(inject fuel) to get the DPF hot enough.

Keeping EGT's as low as possible pulling a load like that up the Ike means keeping them below 1,200F if possible. Those trucks are probably in that range if not higher with a constant load on the engine in the test.

I found this video that will explain what I mean. He is able to reach 800F+ both post turbo and post DPF towing a much lighter load on flat ground. RAM 6.7 Cummins - EGT vs RPM - Lugging

If you look at other videos he has done about regens, you will notice how low EGT's are when not towing under a steady load so an active regen is required in those occurrences.