Stephen Foley: Price is the clincher for greener vehicles

US Outlook: It is a happy coincidence that the US government should have unveiled the new fuel economy stickers that must be placed on new vehicles in car showrooms from next year just as soaring petrol prices are one of the bigeconomic and political debates of the moment.

The sticker is a blizzard of information, including miles per gallon data and sliding scales showing how a car performs on fuelefficiency, carbon emissions and exhaust fumes, relative to other vehicles, but the stroke of genius is a big number in the top right corner saying: "You save $X,000 in fuel costs over 5 years" (compared to the average vehicle).

The invitation is to buyers to subtract that number from the sticker price of the car, adding yet another push – as if the prospect of $4 per gallon gasoline were not enough – for US drivers to seek out more fuel efficient vehicles and help ease the global warming that too many of them don't believe in.

Environmentalists tended to prefer a less sophisticated system, that would assign a grade from A to D to each vehicle, based on its environmental impact, and some were vocal in their criticism of the chosen design. But a grade would have provided no nuance between different vehicles in the same class, and been unlikely to have shifted the suburban mom from her choice of an SUV to something smaller with a higher grade. Better to have everyone choose even a slightly greener car.

There is a lot of fine print in the sticker, setting out the assumptions on fuel prices and driving habits that underlie the headline savings (or additional expense)figure in the top right. But there is also a nifty barcode that can be scanned to take drivers to awebsite where they can adjust the figure based on their own likely vehicle use.

All in all, it is a fine use of technology, design smarts and straightforward economic nous. And it might do more to encourage Detroit to produce more fuelefficient cars than all of the emissions regulations and bailout conditions put together.