Hyundai ix-Metro Concept

The Hyundai ix-Metro Concept is a tiny crossover designed to slot into Europe's sub-B car class. It's powered by a turbocharged 1.0L three-cylinder gas engine that's been combined with an integrated starter motor-alternator for a mild hybrid system that generates a combined 123 hp and 115 lb-ft, the starter motor-alternator contributing 7 hp to that total. To add that extra bump in power, Hyundai has added an Electric Double Layer ultra capacitor connected to a 12-volt battery for juice. The relative shortage of power is offset by a low curb weight of less than 2100 lb, so performance shouldn't suffer too much.
While all the power-adders are nice, they're intended for efficiency, not performance. The tiny engine makes use of turbocharging, continuously variable valve timing and direct injection to burn as cleanly and efficiently as possible, emitting only 0.28 lbs of CO2 per mile. Power is routed to the wheels via a six-speed dual-clutch gearbox