The Fiat 500 hatch will be the first small car to benefit from Fiat Chrysler Automobiles’ all-new 12-volt mild-hybrid technology. Comprising a 12-volt belt-integrated starter-generator (BSG) electric motor and a small lithium-ion battery, Fiat claims that its new electrified powertrain is up to 30 per cent more efficient compared to the 1.2-litre four-cylinder it replaces.