Yamaha FJR 1300, great bike!I am saying very few automobiles have roller lifters. My 2018 F-150 2.7 Ecoboost (twin turbo) does not. My 2016 9000 RPM Yamaha FJR1300 does not. My 2007 Prius did not. The valve springs are much stiffer than any power equipment engine I have seen. And while the Yamaha does over 4000 RPM quite regularly the F-150 rarely goes that high but will when pressed. The Yamaha has 85,000 miles, no valve adjustment, but I've checked. The Prius would rev to 4000 in certain situations.
One source claims the EPA phosphorous limit (which limits ZDDP, which is where zinc is found) only applies to 30 weight and lower motor oils. That 10W-40 or 15W-50 is only limited to 1200 PPM beyond which the phosphorous turns acidic.
Am also saying if power equipment engines really needed "zinc" to protect camshafts and tappet lifters, then the manufacturers are negligent in not using roller lifters.
I have a 2008 FJR I bought new in 2008.