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?
