Engine Oil Weights and Viscosity

Written by Lee Wyatt (last updated May 27, 2010)

Some common questions that people have about basic automotive care have to do with engine oil weights and viscosity and what the terms mean. In the case of automotive oil these words are referring to the thickness of the oil.

Most engine oil used today is multi-grade oil, which means that the substance is designed to operate in a variety of different circumstances. You can find this information, from the Society of Automotive Engineers (SAE), on the side of all motor oil products. This classification is what most people refer to when they say "10 weight" or "30 weight" and refers to the classification on the side of the bottle or can that reads 10W40.

10W40 is known as the SAE oil viscosity grade. This is a multi-grade oil. The W is referring to winter and the oil's viscosity during the colder times of the year. This is determined from testing that the SAE conducts to determine the performance of petroleum products during cold weather operation, while also protecting the engine from operating at higher engine temperatures and loads. If you are in an area of the country, or world, that has a warmer climate on average, then you can probably use a single-grade oil.

Author Bio

Lee Wyatt

Contributor of numerous Tips.Net articles, Lee Wyatt is quickly becoming a regular "Jack of all trades." He is currently an independent contractor specializing in writing and editing. Contact him today for all of your writing and editing needs! Click here to contact. ...

MORE FROM LEE

Dealing with Pampas Grass

When you want it, pampas grass can be an extremely attractive ornamental grass for your yard and landscaping. If you ...

Discover More

Moving and Storage Companies

Moving and storage companies are an absolute necessity when it comes time to move across the country, especially if you ...

Discover More

Choosing Tool Racks

Tool racks can be a great help when it comes to organizing your tools and gardening equipment. Only one problem, and that ...

Discover More
More Car Tips

Understanding Grades of Gas

One of the best ways to become an informed shopper is to understand the difference between the various products being ...

Discover More

Which Grade of Gas is Best for My Car?

One common question that people ask automotive experts has to do with the grade of gas that is best for their car. ...

Discover More

Getting Better Gas Mileage While Driving in Town

Getting better gas mileage, while driving in town is perhaps one of the best methods around for saving money during tough ...

Discover More
Comments

If you would like to add an image to your comment (not an avatar, but an image to help in making the point of your comment), include the characters [{fig}] (all 7 characters, in the sequence shown) in your comment text. You’ll be prompted to upload your image when you submit the comment. Maximum image size is 6Mpixels. Images larger than 600px wide or 1000px tall will be reduced. Up to three images may be included in a comment. All images are subject to review. Commenting privileges may be curtailed if inappropriate images are posted.

What is nine minus 1?

There are currently no comments for this tip. (Be the first to leave your comment—just use the simple form above!)

Links and Sharing
OUR COMPANY
OUR PRODUCTS
OUR SITES
 

Copyright © 2025 Sharon Parq Associates, Inc.