Yamaha’s also accustomed to higher Zn/P 4T oils used in motorbikes - the car side of their engine business has to make do with what they have.I will admit that Honda's VTEC > Toyota (Yamaha) VVTL-i because Honda uses cams on rollers even on the high-profile cams. But then again, Yamaha couldn't have anticipated mandated cuts to zinc additives in oil at the time they designed the rockers.
The Ford SHO V6/V8(which Volvo also used) and the Lexus F-car 2UR-GSE called for 5W-30 oil. Both are Yamaha-built/tuned/designed motors. But the Yamaha 1LR-GUE V10 in the Lexus LFA calls for M1 5W-50, a high ZDDP oil(and it’s also dry sump as well). Valve train issues are almost unheard of, except for disintegrating SHO/Volvo V8 cams.