What Engine Oil Should You Use in the Winter?

Winter driving can cause additional stress and damage on your vehicle. Whether you’re navigating heavy snowstorms or just experiencing cooler temperatures, there are several ways you can protect your vehicle this winter. One important decision to make is to determine which oil is best for high mileage engines in winter. Learn how to compare oil types, understand the difference between synthetic and conventional oil and choose the best oil for your winter driving.

The quick answer is that in most all cases you can trust the dual-grade oil recommended in your owner's manual, although it may have multiple options depending on the climate you live in. If your engine has more the 75,000 miles on it, it is best to fill up with high mileage oil, regardless of season. Continue to read more about the affect of winter on motor oil.

Understanding Oil Types

There are many different brands of oil. Some oil brands include additives meant to clean your engine or perform better under certain conditions, while others are more cost-effective for general driving. All major oil brands, however, use the same system to categorize oils. Shop for oils based on the oil weight.

Oil weight is expressed with two numbers (i.e. 5W-20, 10W-40, etc.). Each of these numbers are essential to understanding how that particular oil weight will perform in winter and summer driving conditions.

The first number is the winter viscosity rating, or the viscosity when your oil is at zero degrees Fahrenheit. That’s why that number is followed by a W. The second number is the viscosity rating for hot oil, typically measured at 212 degrees Fahrenheit.

A low beginning number, typically 5W, means that your oil will continue to flow well at low temperatures. Too thick and the oil won’t properly flow and lubricate your engine’s moving components. However, the second number should be higher for optimal functioning. A high second number allows your oil to stay at a reasonable thickness when heated, as hot oil can easily become too thin to adequately coat your engine’s moving parts.

Nearly every motor oil comes with 20% additives. These additives include:

  • Friction modifiers
  • Dispersants
  • Viscosity index improvers
  • Detergents

Choose the brand you trust or ask your local mechanic or an AutoZone associate to determine which additives are most important for your region, vehicle and driving habits. Depending on your vehicle, you may need to look for an oil that contains additional detergents or friction modifiers for best performance.

When selecting your oil weight, be sure to consult your owner’s manual to ensure you fill up with the correct weight oil for optimal engine protection and performance.

Choosing Synthetic or Conventional Oil

Oil can be synthetic or conventional, or even a blend of the two. Find out what type of oil you’re currently using and determine whether you want to upgrade to a different oil type or continue to use the same, reliable option.

Conventional oil is the most cost-effective option. Unless you’re driving in extreme conditions or driving a luxury vehicle with a high-tech engine, you should be able to find a suitable conventional oil for your engine. Synthetic oil, on the other hand, is the purest, most premium oil on the market. Synthetic oil continues to flow at a reliable rate through a wider range of temperatures, making it an ideal option for high-speed driving or for winter travel.

For a better balance between synthetic and conventional oil, you can choose a synthetic blend. This balanced option gives you a reasonable range of use without the price tag of full synthetic.

If you do your winter driving in a vehicle with more than 75,000 miles on the odometer, then the best choice for you is high-mileage oil. This rugged option still comes in oil weights suitable for cold temperatures, but also is designed to last longer. Typical conventional oil may not be suitable for vehicles who have clocked in over 75,000 miles. Choose a specialized oil designed for higher mileage use to keep your engine running strong.

How Winter Affects Engine Oil

Now that you’ve determined the type of oil, it’s time to find out the best oil weight to achieve optimal viscosity in the winter, which you can do by consulting your owner’s manual or looking it up on our website.

Why is viscosity important? Your engine oil needs to stay within a particular range of viscosity for optimal lubrication. Thin oil may not coat friction points properly, but thick oil won’t move quick enough to keep your engine moving.

Driving in winter exposes your vehicle to extreme temperature fluctuations. From the bitter cold of a long winter’s night to the burning hot temperatures of your running engine, your vehicle needs oil that can perform well under extreme conditions.

When to Change Your Oil

Even the best oil gets dirty. Investing in top-quality oil isn’t going to help your engine run properly if it isn’t consistently changed. Consult your owner’s manual and your oil to see how often you should change your oil.

If you aren’t sure, contact your local AutoZone store or mechanic to determine whether you’re due for a change. Old oil is worn-out and clogged with contaminants, which can compromise it’s viscosity rating. Routine oil changes allow you to get the most out of your investment and keep your engine running smoothly.

When your oil is low, it may be tempting to simply top it off and continue driving. While this may be a short-term solution, there are a few considerations you need to take into account. First, mixing old oil and new oil doesn’t clear it of any contaminants, so you’ll shorten the lifespan of your new oil. Second, if your new oil is of a higher quality or different weight than your old oil, your could reduce its effectiveness. Finally, you should change your oil filter and perform other essential maintenance steps every time you change your oil. Topping off your oil instead of changing it could cause other maintenance steps to be neglected.

The Best Winter Engine Oil

Now that you understand the different weights and types of oil, it’s time to select the best winter engine oil for your vehicle. Which oil is best for your car and your geographic location? The exact brand and type of oil depends on your vehicle and driving style, but dual-grade oils are the best options for winter engine oil because they are more versatile and ready to work at low temperatures. You can find oils that are made for your engine by entering your vehicle’s information to use our oil type lookup. Whether you face sub-zero temperatures or barely reach freezing during the winter, choose a dependable oil for your vehicle in order to avoid engine damage and undue friction.

Advice, how-to guides, and car care information featured on and AutoZone Advice & How-To’s are presented as helpful resources for general maintenance and automotive repairs from a general perspective only and should be used at your own risk. Information is accurate and true to the best of AutoZone’s knowledge, however, there may be omissions, errors or mistakes.

Be sure to consult your owner’s manual, a repair guide, an AutoZoner at a store near you, or a licensed, professional mechanic for vehicle-specific repair information. Refer to the service manual for specific diagnostic, repair and tool information for your particular vehicle. Always chock your wheels prior to lifting a vehicle. Always disconnect the negative battery cable before servicing an electrical application on the vehicle to protect its electrical circuits in the event that a wire is accidentally pierced or grounded. Use caution when working with automotive batteries. Sulfuric acid is caustic and can burn clothing and skin or cause blindness. Always wear gloves and safety glasses and other personal protection equipment, and work in a well-ventilated area. Should electrolyte get on your body or clothing, neutralize it immediately with a solution of baking soda and water. Do not wear ties or loose clothing when working on your vehicle.

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