Imagine you are driving your car one day and feel it pulling to one side. Next time you fuel up, you walk around and realize at least one of your tires is getting low. You know that checking tire pressure is an important aspect of vehicle maintenance. And you know that low tire PSI can be dangerous, impact your fuel efficiency, and even speed up tire wear. But you don’t have the quarters to turn on the gas station compressor and top off your tire pressure. Well, if you live in certain states, the gas station is required by law to give you free air–all you have to do is ask for it.

Which states require gas stations to give you free air for your tires?

California and Connecticut require all gas stations and service stations to give customers free air for their tires. But in both these states, some stations still set up coin-operated tire compressors. If you don’t know the law, you might pay for free air.

If you stop at a California or Connecticut gas station with a coin-operated compressor, first park your car within reach of the hose. Then, go inside and ask the cashier to turn on the air compressor. Some of them will have a button near the register. Others may tell you there is a trick to turning on the machine without paying, such as pressing the “on” button three times.

In California, the law even specifies that the station must have a tire pressure gauge available for its customers. The Connecticut law does not even specify customers, but reads that the station must give free air “to any individual requesting to use it to inflate tires.”

How can you get free air for your tires?

Some states, such as Florida, have opted to install free compressors at all their rest areas. In addition, some gas station chains have free air compressors at every branch, regardless of the state in which these branches are located.

According to The Coupon Project, the following gas station chains may offer free air near you: GATE, GetGo, QuikTrip, Royal Farms, Rutter’s, Sheetz, and Wawa. Even if you don’t have any of these chains in your area, you may be able to find a gas station with free air listed in the user-generated database FreeAirPump.com.

Last but not least, if you have a dangerously low tire PSI you can always pull into a local garage, explain your situation, and hope they are feeling generous. Many service centers will be happy to throw you a line and let you air up your own tires.

Businesses you frequent may already provide a tire compressor

Think about other places where you are a customer that might include air with the service you already pay for. For example, the tire shop where you bought your tires might have sold you a warranty, including free air. Or the dealership where you bought your car might offer lifetime tire pressure checks and top-offs. If you are going in for a service such as an oil change anyway, you can ask the mechanic to check the air in your tires, and they almost certainly will.

Finally, think of places where you are a member. For example, Costco, BJs, and Walmart’s Sam’s Club all have tire service centers and offer air. Some will only air up tires you bought there. Others offer air to every member.

Next, double-check whether you have everything necessary to change a tire by the roadside or see how to inflate your tires yourself with a gas station compressor: