OK, The advantages of running a HDMO such as Chevron Delo 10w30 is greater degergent and higher antiwear additives, namely ZDDP. But I was wondering if there are any disadvantages to this. Perhaps there are. In browsing the Redline Oil site they stated the following: "The diesel engine oils contain significantly greater detergency and total base number (TBN) which helps keep the engine clean. This additional detergency is not recommended for gasoline engines since it could increase the tendency for spark plug fouling." (Redline Website, Our Products, Drain Intervals) What do you all think? If true, maybe we could mix half Delo and half Valvoline VR1 Racing Oil, which is high in ZDDP, but has reduced detergents, to get an oil with about the same detergent as PCMO, but higher ZDDP.