TomC I went into the shop and read the label on the drums the CF-4 15-40 400 is for the newer engines but the drums I have for my two cycle engines and I have 11 of them in different equipment reads Delo100/ 400 CF-2 40 W so I am not confussing anything and these are new drums I just got last week .I spoke with my oil supplier for a few minutes and was told the 2 in CF rating stands for single weight oil
David
