10W30 vs 10W40 A Battle of Automotive Lubricants - Who Will Reign Supreme?

In this matchup, 10W40 oil is slightly thicker than the 10W30 variant. The high-temperature viscosity plays a crucial role; remember, the higher the number ... 10W-30 and 10W-40 are very similar, folks living in very cold areas may opt for a 5W-30 and folks living in extremely hot climates may select a 20W-40/50. 10W30 and 10W40 are made from the same base (assuming we are comparing oils from one manufacturer) with different amounts or types of polymers ( ... A 10W30 is a 10 weight when cold and a 30 weight when hot, but a hot 30 weight is still a hell of a lot thinner than a cold 10 weight. I run 10w30 VR1 in my 200, it sits at 25+ psi at a hot idle in 90-degree Tennessee heat. If your crank bearings are in spec, 10w30 is perfectly fine. 10w30 and 10w40 are multi-grade oils this means that they can carry properties of different weight oils depending on the conditions. The Owner's manual tells us to use 10W-30 oil, what would happen if one used 10-40? will this do any harm and why? Choosing Motorcycle Oil: 10W30 vs 10W40 Motorcycle Oil Comparison Learn if it's safe to use 10W30 instead of 10W40 in your motorcycle ... 10w30 is a more all year oil for a very broad range of temperatures. It has more protection for lower temperatures than 10w40 at the cost of being not as good ... Car Engine Oils by Grade: 0w-20 0w-30 0w-40 5w-30 5w-40 5w-50 10w-30 10w-40 10w-50 10w ...