After reading through various threads it seems that it would be ok to use a HD 15W-40 in small lawnmower engines. Father gave me a Troy Built lawnmower that has an electric starting 6.75HP OHV engine on it. Was electric starting rather as the starter gear seems to have chewed itself up a few months after he bought it. I have a jug of Delo 400 that was leftover from an oil change on a GM 6.5L TD and just wanted to make sure it would be ok to use.