The following gas pump habits may seem harmless, but they’re likely costing you money every time you fill up.

1. Topping Off

While topping off your tank when fueling up might not seem like a big deal, it’s among the most common mistakes people make at the gas pump.

According to GasBuddy, over-fueling can damage your engine and reduce performance. Additionally, most gas station pumps have vapor recovery systems, which absorb any excess gas that is released once the car is filled in order to protect the car and environment.

2. Fueling on the Wrong Day

Gas prices change depending on the day of the week. The beginning of the week typically has cheaper gas prices compared to the weekend. Therefore, if you’re starting to get low on gas, don’t wait until Friday or Saturday to fuel back up.

3. Not Going to the Cheapest Station

While it may be more convenient to go to the gas station nearest your house, that doesn’t mean you’re getting the best deal. There are a wide range of gas price apps and websites to help you locate the cheapest gas in your area.