For vehicle owners and drivers, using the right motor oil is crucial to engine performance. But with various different options on the market, you may need help choosing the right one. For starters, you can look at its weight or grade, which consists of numbers, a dash, and the letter W. This rating refers to the engine oil’s viscosity. Here’s a closer look at why this matters to your vehicle.  

Why Engine Oil Viscosity Is Important

Apart from types (synthetic, synthetic blend, conventional, etc), motor oils are classified according to their viscosity. This term is used to describe how thick or thin a fluid is, which allows it to flow.

For engine oil to be effective, it has to be the correct consistency. However, its viscosity varies according to operating temperature. The colder it gets, the thicker and slower-moving the motor oil becomes, and vice versa. For instance, the winter weather calls for thinner oil for faster flow, better lubrication of moving parts, and more efficient heat absorption. However, using the same motor oil in warmer temperatures leads to less engine protection against wear and tear, as well as reduced operational efficiency.

Where possible, choose the recommended grade for your engine as it’s already tried and tested by the manufacturer. Avoid using the wrong grade—anything heavier reduces fuel economy, overloads the engine, and shortens engine life. A lower grade, on the other hand, leads to excessive friction and premature engine failure.

How to Read Viscosity Ratings

The Society of Automotive Engineers (SAE) formulated a number coding system for grading oils according to their viscosity. There are 11 grades—0W, 5W, 10W, 15W, 20W, 25W, 20, 30, 40, 50, and 60, with W indicating its suitability for winter temperatures. The lower the number, the better the oil performs in cold temperatures. 

Most engine oils come in multi-weights or multi-grades, allowing them to perform effectively and provide engine protection at a wide range of temperatures. They usually come with two ratings separated by a dash, with 10W-30 a popular choice for excellent engine lubrication. It can handle winter weather and warmer temperature simultaneously because of its additives, unlike straight weight oils with their single grade. 

When looking for the right motor oil, always check the owner’s manual for the recommended grade. Opt for one with the donut seal of the American Petroleum Institute, which indicates that the oil has passed industry standards for quality.

For premium-quality motor oil with the right viscosity, look no further than Power & Transmission Inc. As the trusted truck parts dealer in Fairbanks, AK, they carry an extensive selection of auto fluids, including coolant, engine oil, and windshield wipers, for semi-trucks, heavy rigs, and large trailers. Call (907) 456-2230 today for inquiries on product availability or visit their website to learn more.