Mini has claimed that its hatch models will be given technological revisions later this year that will enable "jaw-dropping" performance and efficiency figures.
The Mini Cooper D, which is already the cleanest car in the BMW group, will reportedly offer an economy rate of 72.4mpg and CO2 emissions of 104g/km.
Achievement of such figures has been made possible by "high-tech engine tweaks", according to Mini. Hybrid technology or alternative fuel sources have not been used so the Cooper D’s drive quality has not been compromised.
One initiative the automaker has employed is brake energy regeneration, whereby engine drag is reduced by an alternator that only engages when required to charge the battery.
Efficiency is also optimised by a system that utilises the energy generated by an engine on over-run â€“ when descending a hill, for example â€“ to charge the battery.
Cooper D drivers will also be able to use a switch point display facility, which helps users of manual transmission vehicles by selecting the most economical gear in which to drive.
Furthermore, this model will continue to fall in tax band B this year, a fact that Mini described as "the icing on the cake for customers".