Back to all

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

January 26, 2025

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."

Sterling Tire & Auto
34701 Van Dyke Rd
Sterling Heights, Michigan 48312
586-264-7775

Need Service?

Request a Quote

More articles from Sterling Tire & Auto

Helping Your Engine Breathe Easier

October 11, 2026

You may have heard someone tell you its time to replace your vehicles engine air filter and thought, Its OK. Ill do it in a while. While its tempting to put that off, keep in mind that having your engine air filter replaced is one of the easiest ways to maintain your vehicles performance and ef... More

Leaking Oil Isn’t Normal: When a Valve Cover Gasket Needs Replacing

October 4, 2026

Lets say you discover a little oil leak in your vehicle and you think, Its small. Its no big deal. Remember that no oil leak is ever normal, and it might be a sign that your valve cover gasket is failing. That gasket is what seals the top of your engine. It keeps oil inside while your engine ... More

Smooth Operator

September 27, 2026

Were used to bringing a vehicle to a stop and hardly noticing the engines even running when were sitting still. But sometimes you might notice it running rough when youre idling. Your vehicle is shaking, vibrating and making sputtering noises. You may even notice the tachometer on your instrum... More