BMW Group products are officially the cleanest premium cars following independent, industry-wide research into CO2 emissions. The data, compiled by www.cleangreencars.co.uk, also shows that, through its EfficientDynamics programme, the BMW brand has the most improved average CO2 emissions of any premium manufacturer.

A report into average total model range emissions for car manufacturers found that from the period January 2008 to June 2008, BMW recorded an average of 161.64g/km. By comparison the model range averages for Audi and Mercedes were 177.36g/km and 192.85g/km respectively. Even Lexus with its hybrid-based model line-up only managed an average of 194.85g/km, while Jaguar topped 200g/km and Porsche recorded 275.64g/km.

It's a similar BMW success story when looking at the percentage improvements for premium manufacturers over the same time frame. BMW has improved its average emissions by 11.34 per cent – the greatest amount of any premium manufacturer. By contrast Audi improved its model range average by just 5.78 per cent and Mercedes by 4.13 per cent. Lexus and Jaguar only improved by 2.16 per cent and 2.04 per cent respectively, while Porsche actually increased its average model range emissions by 0.63 per cent.

Engineers at MINI have been equally successful in improving CO2 emissions, according to cleangreencars.co.uk, through the MINIMALISM programme – MINI's take on EfficientDynamics. The MINI model range now has an average of 139.64g/km for the period January 2008 to June 2008. The figure for MINI has also improved by 9.44 per cent compared to a year ago – something that cements its position as one of the top three manufacturers with the lowest average CO2 emissions.

Jay Nagley, publisher of www.cleangreencars.co.uk, said: "The BMW and MINI model ranges have seen very significant improvements when it comes to CO2 emissions. The BMW Group should be praised for its leading stance in this area. It's proof that driving dynamics can go hand-in-hand with a green conscience."

The BMW Group will continue to reduce car emissions ahead of EU guidelines. NOx storage capability within a catalytic converter will be offered on certain models in the near future. Engineers are already finalising drivetrain configurations to meet the likely EU6 legislation due to come into effect in 2014.