My dealer suggests 3500 miles for an oil change for my 04 cummins. My truck sees light duty and occasional hauling atv trailers and a slide in camper. I suspect the dealership has more of a profit motive than a service motive, and I intend to follow schedule B for an oil change. My question is: How do I get my oil tested? What is the approximate cost?

 

Go to your local oil supply dealer that sells barrels or bulk. They should have a source to send it and have the sample kit in stock. Prices vary, usually according to the quantity of oil you purchase. Outrite used to be $20.
Don't forget to add coolant conditioner annually.

Howard