Depending on how much wear the engines have, multi-viscosity oil might not be the best choice. I wonder if the folks who don't like detergent oils still wash their clothes by beating them on rocks down at the creek? I'd prefer a straight-weight detergent oil, but I'm old and opinionated.
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!