Can An Oil Change Affect Your MPG? Here's What You Need To Know

Maximizing any internal combustion engine's fuel efficiency involves frequent maintenance, including periodic oil changes. You should be aware of these signs your oil is running low, and don't skip any oil changes. Oil does more than lubricate moving parts. It rids the engine of combustion byproducts and absorbs heat, helping regulate the engine's internal temperature. As oil gets contaminated, it loses its ability to perform any of these functions optimally. This makes the engine work harder to maintain its output, and fuel economy can suffer as much as 12%. 

Selecting the proper viscosity of oil also has an effect on fuel mileage. For instance, pouring 15W-30 motor oil into an engine that requires 0W-30 will lead to excess friction during cold starts, since 15W-30 does not flow as easily as 0W-30 at low temperatures. Even thin oil like 0W-30 will start to thicken and accumulate sludge as the miles pile up, though. When this happens, it won't have the easy-flowing properties of fresh oil, so you might notice a drop in fuel economy and performance.

Keeping your engine full of fresh oil of the correct type and changing your filter regularly helps minimize heat and friction by ensuring there isn't any fuel economy-sapping sludge mucking things up. Using the correct motor oil is a good start to achieve higher mileage, but maintenance will keep the savings flowing. It's important to use the right type and weight of oil, so check your owner's manual or call your dealership's service department to identify what oil you should be using in your car's engine.

There are also some simple engine modifications that can boost fuel economy. Other fuel-saving tips include periodically replacing the air filter, maintaining proper wheel alignment, and using tires with low rolling resistance. Keeping your tires properly inflated to the pressures indicated on the door jamb sticker or in your owner's manual can also help you maximize the mpg your car delivers.