Synthetic oil change-over

That Cat oil is 5/40. I sure would not use that in any of my diesels. Synthetics are a waste of $$ in an RV application. Any of the major diesel oil brands ( Delo, Rotella Valvoline) will work just as well unless you live in Alaska. Dino oils are almost a synthetic. The OP has a C7 with the infamous HEUI fuel pump system. Totally unlike a Cummins. Uses engine oil to operate the injectors ( it is more compacted than that). Cat does not recommend long oil changes with these engines. About 7000 miles between changes as dirty oil will kill the HEUI and the injectors. Repair costs can be over $7000. The HEUI is the weak link in any C7 so pay attention to oil change intervals. Both Fleetguard and Donaldson make a high efficiency oil filter for that application. If your unit only has one fuel filter you should install another. There is lots of info on doing this mod on the net. Make sure you are using the correct fuel filters. If your chassis is a Freightliner call them with your VIN and they will give you the part #'s. Save the money you would have spent on synthetics and buy beer!


Moisheh