We all know that driving slower helps save fuel and cut carbon emissions, but sometimes it is easy to forget when faced with an open road. But car manufacturer Nissan is planning to offer drivers a gentle reminder of the benefits of not putting your foot to the floor, in the form of an intelligent accelerator pedal that pushes back when you try to accelerate too sharply.

The new "ECO Pedal", which was unveiled this week as the centrepiece of a raft of new green announcements from the manufacturer, is based on software that analyses the rate of fuel consumption and transmission efficiency during acceleration and cruising. It then "pushes back" against the driver's foot if it detects excess pressure that is resulting in the car using more fuel than required.

The company said that tests had shown that the system – which also features a traffic light-style display on the dashboard informing when they are driving for optimum fuel efficiency – could enhance fuel efficiency by between five and 10 per cent depending on driving conditions.

Nissan is now planning to introduce the technology to some of its models from next year, although it added that it would be installed as an optional device that drivers can turn off if they wish.

The unveiling of the technology came as debuted prototype versions of new all-electric and hybrid vehicles that it plans to launch in 2010.

It said that the new electric vehicle would feature a new lithium-ion battery that it has claimed will boast superior performance and reliability compared to conventional nickel metal-hydride batteries, while the new hybrid will feature the same battery technology as well as enhanced rear wheel drive and parallel powertrain systems designed to enhance fuel efficiency further.

Separately, the company announced the development of a new fuel cell stack that it claims boasts double the power density of its previous fuel cell technology. It added that the new fuel cell was also more cost effective, as it uses half the platinum found in previous models. Test fleets featuring the improved fuel cells are expected to be operational by the end of the year.

In related news, GreenRoad, the company behind a driver warning device similar to that being developed by Nissan, announced this week that it has continued its recent run of success, signing up coach operator Stagecoach and two UK councils as customers.

The company's technology, which is also currently being trialled by London bus operator Metroline, measures a vehicle's G-force as the driver accelerates, brakes and corners. It then applies algorithms to the captured data to detect if the driver is driving too aggressively and informs them of their performance immediately through red, amber and green lights on the dashboard.

The company claims that as well as improving driver safety, the device can help motorists cut fuel costs and carbon emissions by an average of seven per cent.