Originally Posted By Pacnorthcuda
Originally Posted By 70Cuda383
100k per oil changes on OTR big rigs?! Ok, but how deep are the oil pans? I would never go 10k miles on my gas motor oil changes, but do it willingly on my cummins. Why? 4-5 quart oil pan capacity vs 12 quart capacity. More oil volume means longer till the same PPM of harmful exhaust contaminates to turn the oil acidic, and more longer till the film strength starts to break down because it's not cycled through the bearings/engine loads as frequently.

How many hours are on the engines at 100k miles vs how many hours on your average daily driver that sees lots of idle and stoplight duty?


I work for an oem class 8 manufacturer and I BELIEVE the norm for big rig oil changes is more like 12-25k miles. I KNOW the capacity of most big rig engines is in the range of 9-10 gallons


I do maintenance for a heavy duty truck/trailer fleet. Company units get oil changes at 35-40k miles, most owner operators do the same. A couple guys who run synthetic aren't stretching theirs any further either. However it's worth noting a lot of trucks these days have two or three oil filters and they all take around 40 quarts to fill. With the environment they see, it would be tough to compare them to cars.