Re: Should I Change the Oil or Not
Reply #18 –
It's hard to break old habits but study after study, backed up with wear analysis indicate that most oil is changed far more frequently than necessary. Cummins, on one hand, gives the very conservative recommendation for frequent oil changes. Then, on the other hand, they have the Centinel system which maintains the oil to a functional level of quality. What is that level?
"The oil replacement rate therefore varies in real time, to maintain oil quality at a level that approximates a typical 50,000 mile oil change interval regardless of the engine's actual duty cycle."
One very long running oil change study on a gasoline engine I followed had some surprising findings. They ran extended oil changes, pulling samples for analysis every 1000 miles. The highest rate of engine wear metals, without fail, occurred immediately after each oil change. They found regular filter changes to be more effective than oil changes, with a midpoint filter change they were still at acceptable levels at 20K miles on oil. This was a few years back, big iron v8.