Japanese manufacturers dominate green car Top Ten

Businesses looking to cut carbon emissions and fuel bills across their transport fleet should buy Japanese, according to a major new report from the Environmental Transport Association (ETA) which saw Honda, Toyota, Nissan and Suzuki dominate a list of the Top Ten green cars.

The Honda Insight was named the greenest car on the road, followed by Toyota's IQ and Yaris models.

The recently launched Insight is a new family-sized hybrid, which according to the ETA is already providing stiff competition for the more established Toyota Prius.

The report, which assessed more than 1,300 models based on a range of criteria, including carbon emissions, fuel efficiency and noise levels, also branded the 8-litre Dodge SRT-10 sports car as the least green car on the market. It calculated that a year driving the Dodge would result in emissions equivalent to the amount of CO2 absorbed by an acre of oak forest.

Andrew Davis, director at the ETA, said that while growing numbers of low-carbon vehicles are now available, the difference between the greenest and the least green cars in Britain remains striking.

"The big problem is not the Dodge SRT-10s and Lamborghinis because there are not many of them on the road," he said, adding that the greater cause for concern was presented by large family cars and 4x4s, such as the Porsche Cayenne.

However, the ETA said the popularity of high-emission vehicles is falling as a result of the new system of emissions-based road tax, which means owners of gas guzzlers now pay more than £400 per year.

The ETA said the study also highlighted loopholes in the government's scrappage scheme, arguing that a motorist scrapping a 1999 Volkswagen Lupo in favour of a 2009 Bentley Arnage could benefit from the £2,000 subsidy, despite the fact the new car produces five times more CO2 than the one it replaces.