I use 15W-40 in every engine at my place- - - -cars, trucks, tractors, lawn mowers, generators, and even a Harley EVO engine. No problems yet, and I buy it in 5 gallon pails from the local farm store at a considerable discount over quart bottles.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!