Geneva 2012: Toyota FT-Bh concept

Toyota's gone all Colin Chapman on us - instead of rolling out a preposterous concept that's powered by laughter and clouds and lollipops, it's taken an ordinary car, simplified it and added lightness.

It's called the FT-Bh and it's an ultra-light petro-electric concept built with cheap materials using normal construction techniques.

Which all sounds terribly dull, but the upshot is a 786kg city car that's bigger than a Yaris (3,985mm long, 1,695mm wide and 1,400mm tall), returns 134.5mpg (more than two times more efficient than a 1.0-litre Yaris), emits 49g/km (around half as smoky as a 1.0-litre Yaris) and is made from ordinary stuff carmakers already have access to.

The super-light shell's been built using a mélange of high-tensile steel, aluminium and magnesium. And because there's not as much load on the body structure and suspension, Toyota's managed to pare down the other stuff and save more weight. Which includes the engine - a baby 60kg three-cylinder 1.0-litre. The rest of the hybrid drivetrain's shrunk too; it's almost 90kg lighter than the Hybrid Synergy Drive system you get in a Prius.

To minimize on fuel guzzling, there's an extremely slick - if a little revolting - outline. Underneath the concepty design guff - which includes a roof formed to "represent the way fabric can be stretched taut between fastening points" it's got a drag coefficient of just 0.235.

There are air curtain intakes in the front, special streamlined alloy wheels, cameras instead of door mirrors, deleted door handles (you get latches instead), a pagoda-style roof with a dropped rear section, and a sharply cut bottom that incorporates an air outlet slit and an underfloor spoiler to smooth the flow of air away from the vehicle. That means it cuts through Earth's atmosphere more efficiently than a Porsche 918. Which is nice.

Toyota wanted to reduce electricity consumption, too - by employing clever men that know many baffling algorithms it's reduced the power used by the LED headlamps, interior lighting and other electrical components by about 50 per cent of a normal car's. It's even fitted special glass for maximum thermal efficiency and slapped on matte paint "for its excellent heat insulation characteristics." And we just thought it made stuff look cool...

Reckon Chapman would approve TopGear.commers?