Well the Schaeffer 15w40 is in and the romps are back. Its not the brand of oil that my truck hates, its just 15w40 oil in general. So I'll be looking at an alternative. Cenex makes a CI rated blend called Maxtron and its available in 5w-40 or 15w40. The price is right too. If I buy it by the case its $2.29 qt. which I think is a good price for a blended oil. Has any body had a experience with Cenex lubricants?