As carmakers strive to improve the fuel efficiency of their powertrains, more and more innovative and technical solutions are coming to light. Take Rinspeed’s latest E2 concept car based on the sporty Fiat 500 Abarth. Instead of opting for a complicated and expensive hybrid or electric powertrain, Rinspeed has developed a dual power mode system based on a conventional petrol powertrain that allows drivers to switch between a low power eco mode for slower city driving and a high power sports mode when fast driving is the order of the day.

A button located on the E2’s dash switches the car’s power output between the high setting of 160hp (120kW) and low setting of 60hp (45kW). At this lower setting, the E2 consumes just some 4.0L of fuel per 100km (58mpg), while at the higher setting fuel consumption deteriorates to 7.0L/100km (33mpg).

Rinspeed uses a special ECU management system to alter the power output of the E2, and the company envisages this modification being applicable to virtually any vehicle with a modern internal combustion engine.

Rinspeed will showcase the E2 concept at next week’s Geneva Motor Show alongside the previously reported iChange shape-shifting car.