A new 1.2-litre 'Dualjet' petrol engine, set to be introduced to the Suzuki Swift range in 2015, is claimed to offer significant improvements in efficiency.
The engine, which is currently undergoing evaluation by Suzuki GB, reputedly averages 65.7mpg and emits 99g/km of CO2. Consequently it betters the existing 1.2-litre petrol by 9.2mpg and 17g/km respectively – and is also exempt from VED.
Suzuki has achieved these consumption and emissions reductions through a series of engine upgrades. Primarily, instead of one fuel injector per cylinder, the new Dualjet engine utilises two.
That means that each of the eight intake ports in the 16-valve engine gets its own injector, rather than the two intake ports of every cylinder having to share one, resulting in more precise control and finer fuel atomisation.
Using an injector per port also means that the injector itself can be positioned closer to the back of the intake valve, further improving atomisation and delivering additional efficiency gains.
Other modifications to the engine include redesigned intake ports, combustion chambers and piston crowns, oil cooling jets for the underside of the pistons, a new exhaust gas recirculation system, start-stop and a hike in the compression ratio from 11.0:1 to 12.0:1.
Maximum power output is slightly reduced, from 93bhp to 89bhp, but torque is up from 87lb ft to 89lb ft. Suzuki has also altered the Swift's gear ratios slightly to offer improved flexibility on the road.
The new Dualjet engine will initially be offered in two-wheel-drive SZ4 models. Three-door versions will cost around £14,500, five-door models approximately £15,150 – a premium of some £500 over the standard 1.2-litre Swift.