Average CO2 emissions for cars ordered on Zenith’s salary sacrifice car schemes this year are 99g/km: more than 20% lower than the average for new car registrations  in 2014.

SMMT figures showed the average CO2 of new cars bought last year was 124.6 g/km.

The fall can be attributed to increased uptake of alternative-fuelled cars, said Zentih, with the continued drop in average CO2 emissions for new petrol or diesel cars.

The culture of the schemes incentivises take-up of the lowest emitting cars, it added. Alternatively-fuelled cars now account for 12% of all Zenith’s salary sacrifice car scheme orders. This compares to 2% for new car registrations in 2014, according to the SMMT report.

Across traditional company car schemes, average emissions for new cars ordered this year have dropped to 108g/km, from 113g/km a year ago.

The decrease has been due to factors including lower emissions for new cars, the benefit-in-kind tax structure, increased uptake of alternatively-fuelled cars and changes to capital allowances which have led to lower emissions caps and incentive schemes.

Ian Hughes, commercial director for Zenith, said: “As the tax regime continues to incentivise low CO2 emitting cars and manufacturers are advancing their technology, through hybrids and electric cars in particular, we are continuing to see significant falls in emissions each year.

"Drivers and companies are also benefitting from improved fuel economy and lower fuel bills.”