Gasoline in Oman costs $2.35 per gallon as of last week. If you plan on renting a car in Oman, then set aside a budget for the cost of gas based on how much driving you imagine doing. If you change your mind about renting a car in Oman, Algeria has some of the lowest gas prices in the world at $1.25 per gallon as of last week. Hong Kong, in comparison, has on average the most expensive prices at $11.70 per gallon but is still a great option for those looking to rent a car.