Mirror, mirror on the wall. Who’s the greenest of them all? The new Polo Blue Motion, that’s who. Ok I’m done with that. Check out the article from scotsman.com

A DIESEL car has beaten the world’s best-selling hybrid vehicle, the Toyota Prius, to the top spot in a new government guide to greener motoring.

A new model of the Volkswagen Polo, which will be available in Britain in October, produces just 99 grams of carbon dioxide () per kilometre - five grammes fewer than the petrol-electric hybrid, Prius.

The Prius has become synonymous with environmentally minded celebrities, such as Leonardo DiCaprio, but the new Polo Blue Motion could prove even greener for some drivers.

Diesel cars dominate the government’s new ‘Act on ‘ list, with officials advising motorists who drive predominantly outside towns and cities to choose them over petrol cars.

However, car-buyers who do most of their driving in urban areas have been told to consider petrol-powered cars instead.

This is because diesel engines produce more harmful pollutants, such as particulates and nitric oxide and nitrogen dioxide (collectively known as NOX).

The number of diesel cars on Britain’s roads has nearly tripled over the last decade to 6.1 million last year, and they now account for 22 per cent of cars.

The Polo Blue Motion 1.4 TDI 80PS, which includes a diesel particulate filter system, is among the first conventional-engine cars to be exempt from road tax because of its low emissions.

Volkswagen said the Spanish-built model was the most efficient car of its class in Europe, thanks to its engine, low weight and improved aerodynamics.

The Prius is joint runner-up in the tables with the diesel Mini Cooper D hatchback, which also has a particulate filter and will be available next month.

The government rankings, compiled with What Car? magazine, feature the ten lowest -emission vehicles in 14 categories, from superminis to luxury cars. However, some models in the three largest car categories, including all those in the performance cars list, are in the highest road-tax band, designed for the most polluting vehicles.

The rankings use emissions data from the government’s Vehicle Certification Agency, which is responsible for conducting the official tests to determine the emissions from cars.

Stuart Hay, the head of policy at Friends of the Earth Scotland, said: “Unfortunately, no account is taken of other local air pollutants that come from diesel cars, so the public might not necessarily be buying the most environmentally friendly car overall.”

Ed Dearnley, a policy officer with the National Society for Clean Air and Environmental Protection, said: “If most of your driving is in cities, diesel cars might not be as good for the environment as you might think.

“Particulates and NOX increase lung cancer and cardiac diseases, and make existing conditions, like asthma, worse.”

Jim Fitzpatrick, a UK transport minister who is due to launch the list today, said: “By choosing the car with the most fuel-efficient engine in its class, drivers could reduce their engine emissions by 24 per cent and potentially save a quarter on fuel costs.

“The car you choose can help reduce your impact on the environment, and save money.”

Steve Fowler, editor of What Car?, said: “These rankings are exactly what consumers need to make an informed choice about the car to buy to minimise fuel consumption, save money and help tackle climate change.”