LOS ANGELES — A couple of dozen electric cars with fuel cells under the bonnet (in place of the more usual flat-pack of batteries beneath the floor) have been zipping around your correspondent’s neighbourhood for the past few years. Most are FCX Clarity models from Honda, all in the same rich crimson colour. A couple of others are silver F-Cell station wagons made by Mercedes-Benz. These experimental vehicles are leased to selected users for trial periods while their manufacturers see how the hydrogen-fuelled cars survive the cut and thrust of Los Angeles’ traffic.

So far, most seem to have acquitted themselves rather well. Meanwhile, their drivers can feel rightly smug about the only emission from the exhaust pipes being water vapour. Another plus is that the fuel-cell vehicles are largely free of the ‘range anxiety