The 4 Reasons Winter Temperatures Lower Your Gas Mileage
Many people visit their dealership or auto shop in the winter complaining that their gas mileage has decreased. They are usually concerned that there may be an issue with their car. Most of the time, it’s simply the colder weather and time of year. Here are four reasons your gas mileage may decrease in winter:
1. Warming up your car. Warming your car up is a common thing to do in northern climates during the winter. It’s nice to get into a warm car when it’s 20 degrees outside and it can help melt any ice that has accumulated on your car. However, if your car is running and it’s not moving, you’re getting zero miles to the gallon. If you live in a place where you frequently have to warm up your car, zero miles to the gallon is going to add up and you may notice a decrease in your overall gas mileage.
2. Lower tire pressure. Tire pressure goes down a pound for every 10 degrees decrease in temperature, which means your tire pressure decreases quite a bit when the weather gets cold. Tire pressure has the biggest impact on fuel economy. If your tires are under-inflated, more resistance is created, which uses more fuel. The U.S. government is so convinced that tire pressure is important for fuel economy, that it has become mandatory for all car manufacturers to include a tire pressure sensor.
3. Your engine is less efficient in cold weather. Your engine is most efficient at its operating temperature and when it’s colder, it takes longer to get there. Oil gets thicker in colder temperatures and it needs to thin out to better circulate through the engine. When the temperature is cold, the engine tries to heat up as quickly as possible, which causes it to idle faster. This can have a negative effect on your gas mileage.
4. Different gasoline additives. Gasoline has different additives in the summer and winter. According to HowStuffWorks.com, “During the summer, pollution is a frequent concern due to increased levels of smog and ozone, which can harm the lungs. Summer-grade fuel has a different Reid Vapor Pressure (RVP) than winter-grade fuel, which contributes to its being (marginally) more eco-friendly.” This difference in additives probably isn’t going to change your fuel economy that much, but it may reduce it slightly.