Choosing the Right Winter Motor Oil

If you live where winter takes a deep hold in your area with temperatures regularly staying in sub-freezing territory, then having the correct oil viscosity is essential before the season arrives. As temperatures plunge, your motor oil thickens and that can mean sluggish starts along with added engine wear. Let’s examine what oil grades are along with the manufacturer specifications and the steps you must take to make a safe switch.

SAE Ratings Explained

Every motor oil comes with a Society of Automotive Engineers (SAE) rating. It may have a single rating such as SAE20 or an alphanumeric rating such as 5W20. The W stands for winter while the first number measures cold-start viscosity, while the second number measures hot-running thickness. The good news is that your owner’s manual describes the precise ratings for your vehicle under summer and winter conditions. Follow those and you are good to go.

But that does not explain the importance of making the switch. What you should know is that lower temperatures mean thicker oil and slower circulation, while higher temperatures mean thinner oil and reduced film strength. Quite frankly, engines rely on quick oil circulation to minimize wear at start-up. Notably, modern synthetics do that best as they are designed to maintain better cold-flow than conventional motor oils.

Making the Switch

When is the best time to switch oil grades? Typically, that change should occur in November, especially in colder climates. If you live where winters are mild, you can keep with your current grade. However, even in areas where temperatures slip below freezing and warm up during the day, your vehicle may benefit from the change. For everyone else, November is an ideal time to switch or even October, just before deep freezes take hold.

It should be noted that newer vehicles often specify all-season synthetic blends. If so, your vehicle is ready for winter. For owners regularly taking short trips, go with the lighter oil.

Manufacturer Recommendations

Vehicle manufacturers outline the best motor oil weights for your ride. This information may be listed on a placard underneath the hood as well as in the owner’s manual. Some manufacturers place that information directly on the oil cap. This means the best advice comes from the people who designed and built your vehicle.

Some vehicles list standard motor oil, but you can safely consider other options. In cold weather, synthetics stand apart—they’re engineered to flow even when temperatures drop below freezing. That means faster circulation at startup, better protection for critical parts, and less wear over time. When winter hits, synthetic oil simply makes smarter sense.

We recommend choosing premium oil brands, as they often include additives that enhance flow at lower temperatures—crucial for quick lubrication during cold starts. Look for bottles displaying API (American Petroleum Institute) and ILSAC (International Lubricant Specification Advisory Committee) certifications, which confirm the oil meets strict industry standards for performance, protection, and cold-weather reliability. Finally, avoid oils that are too thin as these do not offer enough of a protective film to keep metal parts from wearing.

Winter Ready

An oil change just ahead of winter can extend engine life and save you money in the long run. Choose the right blend and you will supply your engine with the edge it needs to function well under harsh conditions.