Back to all

Oil's Well That Ends Well (Oil Change Grades and Weight)

July 2, 2023

Changing your oil regularly is one of the most important things you can do to keep your vehicle running well.  And knowing the right type of oil to use is also very important. 

Engine oil is classified by weight, but it doesn't refer to how much the oil would weigh if you put it on a scale.  It refers to viscosity, or how easily the oil flows through the engine.  Most engines operate normally at around 210°F/99°C.  The viscosity, or weight, is assigned a number by how well it flows at that temperature.  The lower the number, the more freely it flows. 

Most vehicle engines use what's called a multigrade oil which behaves differently in different temperatures. Multigrade oils have a "W" in their viscosity number that you may have seen on a bottle of oil, something like 5W30.  The W stands for winter and shows how freely it flows in colder temperatures.

That means a 5W30 oil will behave like a 5 weight oil in lower temperatures (less viscous or thinner) and a 30 weight oil in warmer temperatures (more viscous or thicker).  That's important on a cold day because the oil needs to behave like a thinner oil when you start your engine since it need to lubricate engine components immediately to protect the metal components. Then as the engine warms up, it behaves like a thicker oil to prevent friction among those parts.  Pretty neat trick, right?

The type of oil you use can differ depending on what type of climate you operate your vehicle in and how your vehicle is used (carrying big loads, towing, etc.). Your owner's manual contains several different recommendations based on these factors.  Your service advisor can recommend the right oil for your needs.  Like Shakespeare said, "Oil's well that ends well."

Gary Knurek GoodYear
1973 Livernois
Troy, Michigan 48083
248-362-0350

Need Service?

Request a Quote

More articles from Gary Knurek, Authorized GoodYear Dealer

Stop Right There!

July 5, 2026

Your vehicles brakes are only as good as its master cylinder. This part is truly is the heart of your braking system, because if it isnt working the way it should, the rest of the brake system cant either. The master cylinder is what takes the pressure you put on the brake pedal and ultimately... More

Why Timing Belt Maintenance Can Save Your Engine

June 28, 2026

One part of your vehicle you probably never think of is the timing belt. It coordinates the rotation of the crankshaft (which converts the up and down motion of the pistons into rotation motion) and the camshaft (which opens and closes your engines valves). Its vital that the timing of these mov... More

Today’s Headlights: Brighter, Smarter… and Harder to Replace

June 21, 2026

Maybe youre old enough to remember when headlights were essentially all the same on every vehicle. They were so cheap and easy to replace, most people could do it themselves. Those days are gone. Now, headlights put out more and better light and are more efficient. Those all contribute to bet... More