Back to all

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

September 17, 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."

TLC Custom Exhaust Brakes & Tires
1735 N Main St
Royal Oak, Michigan 48067
248-541-8300
http://www.tlcautocareroyaloak.com

Need Service?

More articles from TLC Auto Care

Smooth Operator (Shocks and Struts)

May 24, 2026

Few of us ever drive somewhere without encountering some pretty rough roads, and it's amazing how well our vehicles are able to smooth out the ride. Thank your shocks and struts. The two parts are similar. Some cars have shocks in the rear, and struts in the front. Others have struts all around... More

What’s That Yellow Squiggly Line Anyway? (What Warning Lights Mean)

May 17, 2026

You may have noticed when you start your vehicle, youll see several symbols light up on the dash. Theyre different colors and shapes, and sometimes its hard to figure out what each of those symbols mean. They are warning lights and symbolize something in your vehicle is sending you a message. I... More

The Untold Truth About Blinker Fluid: Why Your Car Desperately Needs It

May 10, 2026

If youve been ignoring your dashboard, your mechanic, and that one guy at the gas station who muttered bro your blinkers sound dry, then buckle up because today we dive into the critical world of blinker fluid maintenance. What Is Blinker Fluid? Blinker fluid is a high-viscosity, luminescent com... More