The Dark Mystery of Engine Oil

October 7th, 2015 by

Mystery Oil Change

Have you ever stood in the engine oil aisle at your local auto parts store, wondering exactly what those numbers on the label mean? 5W or 10W? 30 or 50? Have you wondered if any of it actually mattered? Well, you aren’t alone. Many people find themselves scratching their heads over the whole idea because engine maintenance is just not something most of us think about on a daily basis. We only think about it when we have to.

Those numbers can be a mystery, but they really do matter. In fact, depending on where you go or what you do with your vehicle, these numbers (officially known as “weight”) can have a huge effect on the life of your engine. The good thing is that those numbers aren’t too hard to decipher. In this post, we’ll clear up the mystery and the next time you hit the auto parts store, you can just grab and go. Just like the pros.

Why You Should Change Your Oil

Engine oil protects as much as it lubricates. It lessens friction inside the engine that occurs at high speeds and temperatures. But as oil does its job, the additives boil out. Contaminants collect and sludge forms. Before long, the oil is filled with so much foreign material that it begins to grind away at the very parts it was meant to protect. Change your oil according to your owner’s manual instructions and you should never have to deal with words like sludge and contaminants.

It’s all in the Numbers

When it comes to figuring out what weight of oil you need, you first need to consider where you drive, and how you drive. The rest is elementary arithmetic.

The numbers on a quart of engine oil make up what is called the “Viscosity Rating,” which can be thought of like the oil’s thickness. This rating describes the temperature ranges in which the oil will lubricate the engine.

The first number is the low-temperature rating, or how thin the oil is at a given temperature. A rating of 5 means that the oil will be thin enough do its job in temperatures as low as -25 degrees Fahrenheit. A rating of 10 works in temperatures as low as -10 degrees Fahrenheit. The “W” that is beside this number stands for “winter,” which is kind of redundant, but it’s there all the same.

The second number in the rating is the temperature at which the oil is at its optimum thickness. A rating of 30 is best for most cars. The only reason you should consider using a 40, or 50, is if you frequently use your vehicle for towing or other heavy-duty work.

Eliminate the Guesswork

If you are still unsure about which weight of oil to use in your vehicle, check the owner’s manual. You can also check under the hood. Most manufacturers like Toyota print the recommended weight of oil right on the oil cap. If you need to schedule an oil change get one of our oil change coupon specials and visit us at South Dade Toyota.

Posted in Service, Toyota, Used Cars