Using five of its major U.S. airport locations, Enterprise Holdings — owner and operator of Enterprise Rent-A-Car, National Car Rental and Alamo Rent A Car brands — compares its refueling fees to five other major car rental companies.

Enterprise, Alamo and National brands offer three options for refueling to its airport customers. In addition to refueling on their own, customers can prepay for a full tank at a discounted rate or ask for the car to be refueled at a competitive rate, says the company.

Based on May fuel prices and a report conducted by Enterprise Holdings, Enterprise, National and Alamo brands charge the lowest refueling rates:

Average Car Rental Refueling Fees at Major U.S. Airports (May 2014)

The chart reflects charges — which depend on the average prevailing retail fuel price in the area surrounding each airport location — that are based on the local-market price of self-serve gasoline, plus a mark-up not to exceed 50% of the fuel cost, says Enterprise.

According to the company, the Enterprise, National and Alamo brands review local retail fuel prices three times per week. And if the prices change by 3 cents or more in either direction, they adjust their airport refueling prices accordingly.