No one likes to get into a cold car, especially if you have leather or vinyl seats.  The solution may be to start your vehicle and let it warm up to get some heat coming out of the vents. The trouble with the extended warm up is that it can cause reduced fuel mileage during the colder months. If you are like us, you are tracking your fuel mileage to a certain degree to ensure your vehicle stays performing well. Winter shows a negative trend no matter what you do, but there are things you can do to help improve winter gas mileage.

Cold Engines Are Less Efficient

Improving Winter Gas Mileage

The United States Department of Energy has studied vehicle fuel economy.  They reported that a gasoline-powered vehicle can lose an average of 12% in fuel economy during short duration driving at 20ºF.  That’s compared to the same distance traveled in 77ºF.  That most likely accounts for most of the US residents over the winter months to some degree as some residents will see below 20 degrees and some won’t.

A cold engine is less efficient than a warm engine, as each engine has a temperature range that it will have optimum fuel mileage. At start-up, those engines will be out of that optimum range and will use extra fuel as they get to that range.

As a rule of thumb, colder air is more dense and contains more oxygen. The modern fuel injected engines can account for that extra density by adding more fuel to keep the stoichiometric ratio (the optimum air to fuel ratio). That addition means you’re going to use more fuel with a colder engine until it’s within the normal operating temperature.

Idling Wastes Fuel

As great as it is jumping in a warm vehicle, the path to get there usually involves idling the vehicle for an extended period.  Modern vehicles and alarms are adding a great feature that can start the vehicle from a distance, and you can just wait out the cold as the vehicle warms up and defrosts the windows.  All of that idling eats up fuel, and reduces your fuel mileage overall.

The Department of Energy estimates that your cold idling engine can burn 1/4 to 1/2 of a gallon of gas per hour.  If you idle the engine to a warm state every day over the course of the winter months, that adds up to a lot of fuel. A secondary issue that is rarely discussed is the inefficiency of an idling engine that increases deposits inside the engine.  They can start to diminish peak performance over time without proper cleaning.

Poor Weather Conditions Slow Travel

If you’ve driven in snow and ice, you know arriving safe is key to the journey. Most of the time that means reduced speeds on the roads, and sometimes that can be as slow as a crawl. That reduced speed for winter weather conditions also reduces efficiency and you tend to burn more fuel driving so slow.

Winter-Blend Gasoline

As the leaves change color in the autumn months, oil refineries that produce fuel change the blend from a summer-blend to a winter-blend. The key difference between the recipes is that the winter-blend fuel evaporate easier at lower temperatures to assist in cold starting your engine. The summer-blend designed for higher temperatures contains ~2% more energy than a winter-blend gasoline according to the EPA.

How to Fight the Winter Blues

You may read those mentioned items and think fighting against winter weather is a lost cause. You can’t do anything to increase your mileage, right? Absolutely not! While you can’t stop snow falling, you can take steps to increase efficiency and mileage.  Here are some tips to improve winter gas mileage:

Tire Pressure

  • Check tire pressure – As mentioned, colder air is denser.  That means the pressure inside your tire decreases during the colder months.  You can check your tire pressure and keep it up to the manufacturer recommended pressure.  A tire with pressure 10 psi below the recommended pressure can reduce miles per gallon one-percent.  If all of your tires are low, that percentage only increases more and more.  A low tire will also have more rolling resistance through snow, so the mileage can suffer even more.  AMSOIL offers a tire pressure gauge to keep with your vehicle to quickly check pressures.  They also a tread depth gauge.  Ensure your tire tread is ready to battle the snow and ice.


  • Stop excessive idling – The old tale of warming your car to prevent added engine wear is just that.  It’s a tale.  Modern oils are designed to flow at low temperatures.  So idling your engine until the temperature gauge shows warm isn’t preventing excessive engine wear.  It’s only burning extra fuel in the driveway.  Once your vehicle has oil pressure, whether the engine is cold or warm, you can start your journey.  That usually only takes 10 seconds or less.


  • Reduce your extra items in and on the vehicle – We’re all guilty of putting extra things in the vehicle and forgetting to take them out.  Some states require tire chains during the winter months.  But how many take them back out during the winter months?  Traveling in the winter may also require a roof cargo box or a larger roof rack.  Many put them on for a trip and then don’t take them off when the trip done.  We know, it’s a hassle.  But that hassle is the difference in reduced fuel mileage.  Reducing aerodynamic drag and vehicle weight is one way to increase your mileage.  Looking at it another way, it’s not give it away to inefficiency.

Quality Products

  • Use synthetic lubricants – Synthetic lubricants are chemically designed to flow easier at lower temperatures. Added benefits include more wear resistance and internal engine friction reduction. More wear protection and better performance? Absolutely! AMSOIL offers many different engine oil, whether your fuel is gasoline or diesel. Pick what you need the most from your oil: better cleaning, lower viscosity, or longer times between oil changes. AMSOILS has an option for you.


  • Check Your Filters – Your vehicle has many filters that can affect efficiency.
  • Fuel, engine oil, transmission oil, and air filters all keep your vehicle systems running at peak efficiency. If any of them start to lose their ability to screen contaminants out, that may reduce their ability to keep the vehicle running well. A dirty fuel filter can drop fuel mileage by 6% alone, and that will only increase with other filters not performing well.
  • Use Additives Where Appropriate – Fuel additives are a lot of times looked at as an unneeded extra for your vehicle, when in fact they are a great investment into your vehicle’s future. AMSOIL offers both gasoline and diesel fuel additives that can increase octane, improve winter gas mileage, and protect against poor fuel quality. One bottle of AMSOIL P.i. can reduce your emissions and clean your fuel injectors or carburetor for up to 5.7% better fuel economy.

Cylinder Lubricant

Taking simple steps during the winter months can improve winter gas mileage, whether that is taking items out of your vehicle or changing your fuel filter. AMSOIL has products available through your local AMSOIL dealer, BuyGreatOil that will keep your vehicle running at peak performance. Be safe and keep warm out there!

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