Hiring a car in Oslo is probably unnecessary since the city is fairly small and the public transportation system is excellent. Renting a car can also be very expensive, and gas prices in Oslo are notably higher than they are in North America and even many parts of Europe. Parking is also a nightmare in Oslo--meters expire after thirty to sixty minutes and the police impose large fines for illegal parking or overstaying your meter (starting at 500 NOK).
Renting a car can be a good idea if you intend to make a long trip or to travel to rural parts of the country (although buses do reach these areas as well). Before renting, note that manual transmission is regarded as standard in Norway and is found in most cars. You must place a special request for a car with automatic transmission if that is your preference. The minimum age to rent a car is 21 and you must have a valid driver’s license that is at least one year old to rent a vehicle. Finally, note that insurance on the car is mandatory and is generally included in the overall price.
If you do wish to rent a car, there are several major providers in the city.
Avis, Munkedamsveien (tel: 8153 3044)
Budget, Munkedamsveien (tel: 8156 0600)
Hertz, Holbergsgate (tel: 6716 8000).