Back to all

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

August 27, 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."

Tuffy Grand Rapids
610 28th St. SE
Grand Rapids, Michigan 49548
616.452.4425

More articles from Tuffy Grand Rapids (28th St.)

Flat Tire? Three?s the Charm (Tire Repair)

April 13, 2025

For most drivers, at some point youre going to have a flat tire. Depending on how it was damaged, it may have to be replaced. But sometimes, a repair will do the trick, as long as the puncture isnt on the sidewall and the hole is smaller than inch/6.35mm in diameter. Here are the three common w... More

Avoiding Exhaustion (EGR Valve Replacement)

April 6, 2025

No, ERG isnt the sound a pirate makes. Its a part in your vehicle that recirculates exhaust gas to reduce certain gases and pollutants in the atmosphere. In fact, ERG stands for Exhaust Gas Recirculation. One gas our vehicles may make when they burn fuel is nitric oxide, which can play a big ro... More

Why did my vehicle fail its emissions test?

March 30, 2025

We all want to breathe clean air and keep our planet green. One of the ways to do that is by requiring all vehicles with internal combustion engines to pass an emissions test. Thats because these vehicles can be big polluters. Everyone wants their car to pass the test so they can continue the... More