Ford has announced a new powertrain for the fiesta, which adds a 48v mild hybrid system to top level EcoBoost models – that is, those with 124bhp and 153bhp 1.0-litre turbo petrol engines. In a move that follows BMW doing the same thing with its bigger engined stuff (mostly SUVs), the Ford system replaces the standard alternator with a ‘battery integrated starter/generator’ (BISG), which captures brake energy and directs it to a 48v battery pack.
The BISG can power the car’s electrical system as well as syncing up with the petrol engine to either reduce load on it or provide a 24Nm torque boost – which can equate to a 50% torque boost at lower rpms, says Ford. It also means the car can coast with the engine switched off at speeds below 15mph, when it's coming to a stop. According to Ford it delivers a 5% reduction in fuel use. The engine already features cylinder shutdown technology, which will shut-off one of its three cylinders when it’s under light load.
The official WLTP ratings of the 124bhp and 153bhp 1.0-litre EcoBoost models are 57.6mpg and 55.4mpg respectively, which makes them more economical (on paper) than the 94bhp version of the engine, which doesn’t have the 48v system, at 53.3mpg.
The cheapest 48v version of the Fiesta available at the moment is a lower powered Titanium model, at £19,860.
Ford has used the opportunity to make some other improvements to the Fiesta range, which is consistently a best-selling car in the UK and is Ford’s top selling model in Europe. It includes adaptive cruise control including automatic stop and go, speed sign recognition, wireless phone charging, and – unusually but very usefully – repositioning the subwoofer in cars equipped with an optional B&O stereo to liberate more boot space.
A seven-speed twin clutch transmission option for the 124bhp 1.0-litre EcoBoost model is available now too, which Ford claims is 15% more fuel efficient than the outgoing 99bhp EcoBoost automatic, which used a six-speed auto.
Keyword: Ford ‘electrifies’ the Fiesta with hybrid tech of the mild sort