Refueling your rental car will never be a problem on St. Maarten/St. Martin, because there are gas stations every few miles and in all regions of the island. Some offer 24 hour service for the late-night party crowd, and the stations' well-stocked convenience stores provide snacks, beverages and even hot food.
Prices are shown per liter - not gallon! - and the currency displayed on Dutch side gas stations is the Antillean Guilder (NAF) – not the US-Dollar! On the French side, the rates displayed is for the liter, and the currency used is the Euro.
The Antillean Guilder (also called Florin and shortened to NAF) is set at an exchange rate of around 1.80 NAF to 1 US-$. The exchange rate of the Euro to the US-Dollar is more volatile.
The prices displayed on the gas pumps are also in either NAF or Euro. The attendants will convert the total shown for you into Dollars. On the Dutch side, make sure that you do NOT pay the displayed amount in Dollars!
Gas stations don't take credit cards! Make sure you bring cash or see if the station has an ATM machine. The attendants only accept cash.
Services: Usually, there is an attendant filling your tank. Late at night, some stations have changed to self-service with pre-payment on a teller window.
Tires do go flat on the island's roads and the gas stations' compressors are usually of no help in getting a slow puncture back up to pressure. Most of the times, the compressors are out of order. In case of a flat, you might find an easy solution by purchasing a tire-inflation-spray, which also seals small leaks. Try this option before you attempt to change the tire.
Do not drive back to the rental car company on a flat tire! The tire and maybe the rim will be destroyed and you will be charged accordingly.