FOR high-mileage business drivers, the rising cost of fuel - as the value of sterling has nose-dived - has become a major headache. But a new Huntingdon-based company believes a simple modification to a vehicle's engine management system can pay for itself in less than a year. Traditionally, engine tuning has been aimed at increasing performance. But Jason Wilderspin, who founded JWE Automotive Services last year, says eight times as many clients are now asking for the same technology to be used to optimise fuel consumption rather than performance. Typically, re-mapping the vehicle's on-board computer - the engine control unit (ECU) - can save 15 per cent of the fuel used by a turbo-diesel vehicle and 12 per cent for a turbo-charged petrol engine, he says. The figures for normally-aspirated engines work out at around eight per cent. With re-mapping, which takes around a couple of hours with a laptop computer, costing from £300, the savings quickly mount, Mr Wilderspin told The Hunts Post.