All my OPE gets Rotella T6 15w40. That includes a 20HP Briggs mower, a 5.5 HP Briggs pressure washer, a Honda GVC190 push mower, and all my friends/family OPE as well. My jetski, an ‘18 STX15f, gets T6 15w40 now as well, had LiquiMoly PWC 10w40 before.
All OPE also gets a WIX 51348 oil filter or derivative of that.
Outside of the jetski, all my OPE may switch to Supertech dual rated 15w40 in the future.