Just an opinion...... Caterpillar is very diligent with filter design, oil specs, maintenance intervals, and designing their motors for longevity. They develop the fluid change intervals from oil analysis, engine tear downs, and evaluating critical part wear rates and tolerances. We will probably never wear out an engine in a motorhome and these engines see relatively light duty compared to heavy commercial truck fleet use. Given that they create their service intervals from data from the truck fleet analysis it would seem unlikely that we have to shorten the change interval recommendations that are provided. I had read about a Cat C12 teardown at over a million miles of use and the engine still had wear that was within tolerances and they expected another 250k miles before any internal parts were needed to be replaced. I sold an 89 Beaver Contessa last year with about 100k miles on a Cat 3208 and it still did not use oil between changes at 20 years old.
As long as you did not have an overheat condition, some fluid contamination, or have excessive sitting with condensation issues between oil changes I think the Cat service intervals should be fine. You could pull a sample and have the analysis done to see what the oil conditionn is and go from there.
Regards Ed
