However, generally speaking, a 2000 Dodge Ram 1500 would likely use a conventional or synthetic blend motor oil with a viscosity rating of 5W-30 or 10W-30. Again, check your owner's manual for the exact recommendation. The manual will specify the correct viscosity and the API (American Petroleum Institute) service classification (e.g., SJ, SL, SM, etc.). Using the wrong oil can damage your engine.