I decided after breaking the engine in, my 261 deserved the ROYAL treatment. I use 10w30 in central Kansas it works best I think. But whats more important than the oil viscosity is the COLOR. When I have a drip on my concrete, I want to know what it is.. brake fluid, tranny fluid, whatever. So, Royal Purple 10w30 synthetic. Problem is, I don't have any leaks so far! Here is to hoping my problem persists!
