5W-20. 5: This is the oil’s viscosity rating at low or winter temperatures. W: This stands for “winter,” and is part of the “5” rating. 20: This is the oil’s viscosity rating at high temperatures. What this means is that the oil industry scientists, in their labs, have created lubricants that flow better at low temperatures than Fahim Ahmad Zahid Zahid. Because it is thinner, the 10W40 flows well at high temperatures leaving no residue in the engine. The 15W-50 engine oil is better for use during Winter than the 10W-40. 10W -40 is denser or thicker than what most engine manufacturers recommend. 15W, on the other hand, increases wear fuel consumption and reduces power. Let the owners manual for your vehicle help you decide. The manual for my 3.8L Buick says SAE 30 oil is preferred unless the cold start-up temperature is below 32ºF (0ºC) for several times between oil changes. It further says that 15W-40 should be used in other situations, but recommends not using 10W-40 as it could void the warranty. The main difference is that 10W40 oil is thicker than 10W30 oil at higher temperatures. Both have almost the same characteristics – the only difference is the oil viscosity. Sadly, that quick answer probably doesn’t make it much easier to understand. You will first need to know what oil viscosity is and what the numbers of both motor oils mean. As it remains thin and flows easily, 0w40 will act against engine problems like bearing failure. The 5w40 also has a tremendous low-temperature thickness, though slightly below its companion. For hot weather, the two oils’ viscous values are 40. They become thicker; hence, they offer more protection to the engine parts. So the 15W-50 oil is “thicker” at cold temperatures than the 10W-40, therefore it will flow worse on start up; but being a little “thicker” it and maintains its viscosity at high temperatures better than the 10W-40. As few of us ride in the winter, the 15W-50 is a good choice. The Differences Between 10w40 & 15w50 Motorcycle Oil. 10w40 grade motorcycle oil will hold its performance right up to 40 degrees Celsius (104 degrees Fahrenheit), while the 15w50 grade motorcycle oil will hold its performance up to 50 degrees Celsius (122 degrees Fahrenheit). The number before the W tells you how the oil will flow in cold lBZV.

difference between 10w and 15w oil