French start-up Heat2power has been making a little noise in the Hexagone thanks to a new technology that increases fuel mileage using heat energy otherwise dissipated via the exhaust pipe. There are others that use a similar system, but the company claims that their device captures even more energy. The basics include installing an additional cylinder linked to the crankshaft with a clutch that is powered by exhaust heat. The exhaust gases circulate inside a heat exchanger linked to a closed-circuit filled with compressed air. Hot air enters the additional cylinder. Once it has moved the piston, the air goes to an intercooler and returns to the heating unit forming a closed circuit. The system is compatible with any ICE engine, the company claims. Their numbers also say the device reduces up to fuel consumption 20 percent in urban driving and 35 percent on the highway. The company claims that the additional cost for a car is only 300-400 euros.