Average European new car CO2 emissions are falling at a faster rate than ever, and are on course to meet 2015 EU targets, according to JATO Dynamics.

The automotive intelligence provider said last year saw the greatest single-year decline in average CO2 output, as buyers demanded more fuel-efficient vehicles, while the introduction of CO2 based taxes in some markets and national scrappage schemes across Europe favoured smaller, 'cleaner' cars.

The volume-weighted European new car average is now 145.9g/km, almost 20g/km less than 2003, when JATO began collating European CO2 emissions data. Half of all new cars sold in the 21 countries analysed had official CO2 emissions of 140g/km or less, compared to only 23% in 2003.

JATO Consult head David Di Girolamo said: "The pace of improvement is remarkable and shows just how rapidly the industry has reacted to environmental demands.

“In 2003, only 24% of the market achieved an average of 130g/km. This was 40% by 2007, 51% in 2008 and 69% last year, already ahead of the 2012 EU target. This achievement is even greater when set in the context of new cars becoming larger, safer and better equipped, as consumer demands reach ever higher."

According to JATO, the progress in CO2 emissions was due to several factors: vehicle developments - including more efficient petrol and diesel engines, hybrid powertrains, more sophisticated transmissions, low rolling-resistance tyres, improved attention to detail, aerodynamics, stop-start technology and regenerative charging systems.

Most manufacturers now offer environmentally-oriented specific versions, combining many of these features, although they can be found individually in a wide range of models and segments.

Jato said: "This progress has been swift and while specific environmentally-oriented versions are a small proportion of overall new car sales, many of the features they carry are filtering through to their ‘mainstream' counterparts. This is a trend that will continue, as engines become smaller, lighter and more efficient."

Taxation is also guiding demand towards these models and technologies while CO2-based purchase and/or ownership taxes have, , in some countries, been introduced in tandem with higher fuel taxes.

Significant rises in fuel prices (due to global oil prices) continue to influence consumers' choice of vehicles.

During late 2008 and 2009, scrappage schemes in a number of European countries benefited the purchase of smaller, more efficient cars, in some cases with customers directly incentivised towards cars with low CO2 emissions.

Even non-scrappage sales have seen a marked shift towards smaller cars, with the largest rise in B-segment vehicles, an effect of recessionary pressure on family budgets pushing many European customers to consider fuel efficiency ahead of other factors, for the first time.

The net result is that volume-weighted average CO2 emissions of new cars in the 21 countries studied fell from 165.3g/km in 2003, to 153.7g/km in 2008. Through 2009, further progress brought the average CO2 emissions of new cars down to 145.9g/km.

Di Girolamo added: "The key point to note is that the rate of improvement has been increasing since 2007, through more low-CO2 technology and specific low-CO2 models on the road. Looking at year on year trends, it appears that, if the current momentum can be maintained, 130g/km by 2015, as required by EU legislation, is achievable."