Go to any city in Europe and you're likey to be knocked over by a commuter in a Smart car -- they're everywhere. But the Smart fortwo cdi stands proud above the snub-nosed horde: it has the lowest carbon emissions of any current production car in the world (with a combustion engine), just 88g/km. Its diesel engine and feather weight mean it's ludicrously efficient, managing an amazing 83mpg.
It might not be the fastest thing we've hit the road in, taking nearly 20 seconds to get to 60mph, but it's very safe for a little box, earning four stars from the gentilhommes at Euro NCAP.
Gadgets are a little thin on the ground, but you get electronic stability and skid control, and you can add a speaker system for around £170, which is a pretty good deal. You can buy one now for around £8,000.
Find out more in our photo story and at the Smart Web site, but not until you've watched Rory do his thang. If you're into using no fuel at all, check out our videos of the Smart ED electric car and its Brabus-tuned twin, which sounds like the Starship Enterprise.