More than 40 million Americans are expected to hit the road this weekend for Memorial Day.  If you’re one of them, here are four tips on how to save on gas:

1.  Use an app.  Apps like Gasbuddy and Waze can help you find the cheapest gas prices at nearby gas stations.

2.  Buy gas at a wholesale club.  Clubs like Costco, Sam’s, and BJ’s often have gas stations attached to them and can save you 20 to 30 cents a gallon on average.

3.  Maintain your car.  Stuff like low tire pressure will reduce your fuel economy and can damage your tires.

4.  Use air conditioning.  It sounds counter-intuitive but air conditioners actually create less drag on the engine than driving with the windows down.