MITSUBISHI has revealed details of its world-first direct injection petrol engine, the GDI, which is already on sale in Japan. The new 1.8-litre unit powers a new generation of the Galant executive range in Mitsubishi's domestic market and will make its UK debut in the Carisma towards the end of next year.

The new engine has the small capacity and high power of a petrol engine combined with the economy of a diesel. The technology can be applied to any size of petrol engine, in line or V configuration. But first off the line is a four cylinder in-line unit with a compression ratio of 20 to 1. Power output is 150PS at 6,500rpm - more than the current 2.0-litre multi-point fuel-injected engine.

The new technology allows an air-to-fuel ratio of 40 to 1 as opposed to the 15 to 1 ratio of conventional petrol engines. This leads to a 25% improvement in fuel economy at urban speeds - which beats a diesel too. At 75mph the fuel saving is 8%. A high rate of exhaust gas recirculation is designed in and NOX levels are substantially lower at all speeds and most importantly by as much as 90% at in town speeds of around 25 mph. Standard specification will include twin airbags and prices will start at around £18,000 - rising to £23,000 for the top of the range models.