Iceland has a large gasoline network. Just watch out that your credit card has a valid pin code with maximum 4 digits. Iceland still has gas stations (self serviced) that only accept 4 digits.
When filling up the vehicle make sure you are using the right fuel. The color on the different fuel types can be misleading. F.e green is often gasoline, black is diesel (not like in the US). The most important thing is to know the difference of Diesel and Gasoline. The pump is well explained and there should be the letters DISEL or BENSIN. Our Bensin (Gasoline) is 95oct. We recommend using a serviced station for the first time and if you are not sure, please ask a service attendant.
Please make sure to use the right key to open the lid. Another common (once a year) mistake is to fill the water tank up with diesel. Please try not to. The water will smell funny and it could lead in replacing the complete water system at your cost.
If you have further questions, feel free to contact us.