The reality is that the oil you choose can make a significant difference in engine performance and wear over time. Here’s how to decode your oil type and why it matters.
A MATTER OF THICKNESS
For the purposes of this article, we’ll focus on multigrade oils, which are the oils most commonly used in cars and trucks. These oils are identified by a number, followed by a “W” and a dash followed by another number. For example, 5W-30 or 10W-30. These are oil grades, established through a system developed by the Society of Automotive Engineers (SAE).
An oil’s grade describes its viscosity, or thickness, at different temperatures. For a clear example of viscosity differences, think about honey, which is very viscous, compared with water, which has very little viscosity.
WHY IT HAS TO BE RIGHT
Vehicle manufacturers develop their engines to operate optimally using specific oil viscosities, so it’s important to follow the recommendations in your owner’s manual.
An oil that is too thick can put too heavy of a load on your engine, worsening fuel economy and ultimately shortening the engine’s life. If your oil is too thin, parts can wear more quickly, again shortening engine life.