Depending on the market, the fourth generation is available with an under-floor mounted or rear door mounted spare wheel. For example, UK vehicles have the spare wheel mounted under the floor, while in Australia and Argentina the spare wheel is mounted on the rear door, leaving space for an auxiliary fuel tank, which is desirable in countries where long journeys in isolated areas may be required. The fuel capacity of the dual tank series four is 150 L compared to 179 L of the series three.