No matter how economically you drive a Caterham, you're unlikely to get 131mpg from it.
But that's what a modified Seven managed this week during the Shell Eco-Marathon at Rockingham race circuit in Northants.
The recipe? Start with a 1.6-litre K-series Roadsport and let carbonfibre specialist Axon work over the body. Add lightweight seats, very narrow low-resistance tyres and drive super-economically.
The rules state that cars must drive for 40 minutes and seven laps at a minimum of 15mph.
The technique was to floor the throttle at around 15mph in third gear, accelerate up to 25mph and then turn the engine off and coast.
Dr. Steve Cousins, who led the project, told Autocar.co.uk that he thought economical driving - not exceeding 2000rpm - could deliver economy around 50mpg if the car were driven on the road.
The Caterham was the only car in the competition to have started life as a road-legal vehicle.
Axon is in talks with Caterham about returning to Rockingham next year with a 500cc engined Caterham in search of an even higher mpg figure.