Stuff about fuel.
All WRC competitors must use control fuel as deemed by the FIA. Special octane mixtures are not permitted. All fuel for the WRC is supplied by Carless Fuels. For Spain, 29,000 litres of unleaded 98 octane fuel was provided in 149 drums containing 194 litres each
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In the allocated refuel areas (where naked flames are not permitted and fire fighters are on standby), competition cars are re-fuelled at a rate of 55 litres per minute via a dry break coupling with two pipes one is a breather, the other carries the fuel
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The Subaru Impreza WRC2001 has a fuel capacity of approximately 80 litres and fuel is stored in a flexible rubber bag tank that is reinforced with kevlar. This is safer than traditional steel tanks and is almost rupture-proof due to its flexibility
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The Impreza has two fuel gauges, accurate to 0.1 litre, one showing fuel in the tank, the other showing fuel used, forming part of the co-drivers display unit
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Weighing 0.79kg per litre, fuel adds a significant weight penalty, so the tank is located as low down in the car as possible to aid positive handling characteristics. The Impreza uses 0.7 litre per km on the average stage, and 0.2 litres per km on the road sections
Source: SWRT Newsletter #6