The arrival of more affordable electric cars in 2011 will mark the start of what could be still quite a slow shift to cleaner and more environmentally sound transport. In the meantime, or as an alternative, anybody planning to buy a new car has a growing choice of conventional diesel and petrol-driven models which achieve roughly double the mileage that similar models would return only four or five years ago.

A puzzle to me is this.  Why aren’t advertisers, pub bores, environmentalists — in short anybody who talks about cars, their impact and their costs — talking far more about these quite startling fuel efficiency figures?

I recently hired a ’10 registered Peugeot 107. I drove it 519 miles in the course of my job, and put in £42 worth of petrol. The handbook promised 72 miles a gallon, and that wasn’t far off.  To do the same trip in our the family car, of about the same size, would havecost about £75 in petrol. And there’s the small matter of not having to submit to the chore of calling in at the petrol station so often: I would like to know who actually enjoys doing this.

Yesterday I saw the new Volvo V50 advertised in the Evening Standard.  It promotes the appeal of this biggish car through these vital statistics, in a way we haven’t seen much before — 70 miles a gallon, and 104 grams per kilometre. The urban cycle is 57.7, and the extra urban is 83.1 miles per gallon. These are impressive figures that few others can match — or want to be seen to be matching, in their adverts.

People buying new cars still put the CO2 emissions fairly low on their checklist, just below the quality of the CD apparently. Not too much concern for the planet, then, just yet. So maybe car manufacturers, and advertisers should turn the whole thing round and appeal directly to their wallets. 70 miles per gallon? how hard to you have to ponder that?