I have a long-range fuel tank. Should I take along extra fuel?

This depends entirely on the capacity of one’s fuel tank. In the desert petrol engines (it varies from make to make) use one litre of fuel to travel 2.5 to 4 kilometres. Diesel-driven vehicles manage 4-5 km per litre. Though the desert-crossing section of the tour (550km) is designed to be managed on one full tank of fuel, the rule of thumb is “better safe than sorry” so bring along a few extra litres in the event of an unforeseen event or emergency.