weight of oil depends on climate and driving style, our shope uses 5w-30 all around unless its one of our race cars in which we use 20w40 racing oil. i have 207k in which i have been beating the hell out of the last 65k on mine and have yet to run into any problems and won't. use the OEM filter and recomended oil unless you use it for anything other than street. yes its a warm running engine, but as