Has anyone else noticed the phenomenal speed at which petrol and diesel engines are being developed into green motive units? The Frankfurt motor show was awash with advanced green concepts and ideas, but the real breakthroughs are in the cars you can buy now and in the very near future, with tailpipe emissions that were in the realms of science fiction only three years ago.

BMW’s mild hybrid tech is easily leading the way. Just about every four-cylinder engine in the range now comes fitted with mild hybrid, fuel-saving kit. Following BMW’s lead, Mercedes and Audi will bring similar technology to market in the near future.

On sale now are a BMW 318d capable of 123g/km and, more impressively, a 520d capable of 136g/km. Amazing figures. Only three years ago you couldn’t buy a Ford Focus with a C02 figure lower than 140g/km.

In 2009 Mercedes will have a 37mpg ML 4x4, followed in subsequent years by a 36mpg S-Class limousine, a 55mpg E-Class saloon and a 61mpg C-Class compact exec. Those are equally breathtaking figures, and more will undoubtedly come.

Cropley’s piece in last week’s mag quoted Richard Parry-Jones saying that, as a fleet average, 100g/km is likely by around 2015-17. With 40g/km commonplace by 2050. In an industry that counts time in model-cycle blocks of five years, that's phenomenal progress.