or,they know most of us hard driving kaki and drives 4 cyl car.
so 30 not suitable....
50 is almost goneand now 40 dominate market.
30 is steadily being used in newer modern engine,even turbocharged engine.i know
this cause my friend pug are recommended to run on that grade of oil.
Modern engine tolerance more precise, probably needing lighter viscosity. 50 weight old faithfully Mobil 1 5w-50 still around.....



