Evitzee
Junior Member
Everybody has their pet theories or knowledge of oil.....but in 45 years of driving which probably amounts to over half a million miles in cars in hot and cold climates, and 100,000 additional miles on two wheels in air and water-cooled engines I have never had any failure or issue with any oil or any engine. I replace the oil as specified by the manufacturer, I've used all kinds of oils and have had good experience with all of them. If you are afraid of using a 5W-40 oil instead of a 10W-30 than go ahead and use what you want, but you are deluding yourself into thinking it makes any real world difference. Don't get hung up on specs and old wives tales.