2015 Ram with Cummins oil change interval

The oil life monitors on our Rams in the Arctic actually seem slow compared to engine hours, but I haven't done any oil samples to disprove its validity/.
These trucks idle ALOT at sub zero temps, some run 24/7. No load driving conditions, 35mph max. We change at 400 hours regardless of meter readings and it takes about 2 oil changes to get to zero on the oil life meter. Maybe the new engines are very efficient with preserving oil quality, dunno, but for example, my truck has about the most road miles and least idling in the fleet and I average about 4mpeh (miles per engine hour).
If I was going to trust the oil life meter, I'd run a blackstone test or 2 for comparison.

N-Trouble wrote:

ScottG wrote:
Just anote, if a programmer is used then the oil-life meter is meaningless.

Explain...

It's because most programmers advance the timing* (to what it was years ago) and this causes a heavier soot load for the oil because the air fuel mixture is in the combustion chamber longer prior to ignition.
A programmer also puts more fuel in which also causes more oil degradation.

The oil life meter can't accurately take these factors into account because it changes what the ECM knows as a set value.

*Another side effect of advancing the timing is that it limits your max safe EGT because the heat is in the cyl longer. So if you had a max safe temp of 1500 degrees then it may only be safe to 1200~1300 degrees with advanced timing.

downtheroad wrote:
Lots of discussion and confusion and skepticism about this topic...
GOOD LUCK GETTING A DEFINITIVE ANSWER ON THIS ONE...

Electronic sensors throughout the drivetrain send information about engine revolutions, temperature and driving time and other factors to the car's computer. The data is run through a mathematical algorithm that predicts when the oil will begin to degrade. The light comes on well in advance, giving the owner time to get the car serviced.

I follow the oil life monitor..But...Change it when it shows around 20%. And or, I also change it it gets around 8000 miles and still shows lots of % life left...kind of a combination between new and old school.

Others change oil at 0% while others still stick to the old 3000 mile rule..

Actually this answer is spot on... Also the truck tracks the number of regens as part of the algorithm as well.

BTW... Probably a wise move to unload the '06.

ScottG wrote:
Just anote, if a programmer is used then the oil-life meter is meaningless.

Explain...

Just anote, if a programmer is used then the oil-life meter is meaningless.

Lots of discussion and confusion and skepticism about this topic...
GOOD LUCK GETTING A DEFINITIVE ANSWER ON THIS ONE...

Electronic sensors throughout the drivetrain send information about engine revolutions, temperature and driving time and other factors to the car's computer. The data is run through a mathematical algorithm that predicts when the oil will begin to degrade. The light comes on well in advance, giving the owner time to get the car serviced.

I follow the oil life monitor..But...Change it when it shows around 20%. And or, I also change it it gets around 8000 miles and still shows lots of % life left...kind of a combination between new and old school.

Others change oil at 0% while others still stick to the old 3000 mile rule..

No it does not analyze the oil but the gauge is based on exhaustive testing and is known to actually be conservative - meaning there's more life left in the oil than it says.
It's a great feature that you can actually go by.