Mazda's efficiency push

Mazda will replace virtually its entire range of engines and platforms in the next three years to help reduce the fuel consumption and CO2 emissions of its model line-up.

The target is for a 30% improvement in fuel economy and a 23% reduction in CO2 by 2015. This will come on top of improvements of 19% and 16% respectively in the past seven years.

Clean diesels, more efficient petrol engines, petrol-hydrogen hybrids, weight reductions, stop-start systems and a new six-speed automatic transmission with the efficiency and performance of a manual will all play a part.

The latest Mazda 2 supermini shows what is possible. It is 100 kilos lighter than the old model, without any loss of safety, performance, space or content.

Mazda aims for weight savings of between 100 and 200 kilos when other models are replaced.

It will achieve this through greater use of computers in design, new manufacturing processes and, as a last resort, using lighter but more expensive materials.

The next stage of the economy drive will entail the introduction of a clean diesel engine and a petrol unit with a stop-start system during 2009.

The new 2.2-litre diesel develops 183bhp and 296lb ft of pull, but uses no more fuel and emits no more CO2 than today's less powerful 2.0-litre.

It also produces fewer oxides of nitrogen and soot particulates both of which have been linked to breathing difficulties among city dwellers.

The stop-start system is likely to be seen for the first time when the Mazda 3 is replaced. It is currently undergoing trials allied to a new 149bhp direct-injection 2.0-litre petrol engine.

Mazda is particularly proud of the speed and smoothness of engine restarts, claiming it out-performs BMW's similar system.

Petrol-hydrogen hybrid vehicles, which allow cars to run on either fuel, are unlikely to be seen in the UK for years. However, a duel-fuel Mazda 5 will go on sale in Japan by the end of the year, and Mazda sees huge potential for a rotary-engined petrol-hydrogen car.