Using their heads: Lotus showcases hemp-based body plastics

Lotus has taken up the green motoring cudgels with radical gusto, coming up with an Elise that supplants the more common approach involving changes to engine and drivetrain with construction methods straight out of mid-1970s Nimbin.

Not since Cheech and Chong's Up in Smoke has a car maker come up with a vehicle so green. Like the American comedy duo's van in that late 1970s stoner classic, the Eco Elise features body panels made of hemp and, well, a different kind of resin to what you might be expecting by now. The hemp replaces the glass fibre reinforcement matting in the moulded plastics from which it's long made its bodies.

The only change to the standard Elise drivetrain is the addition of a dash indicator telling the driver when to change gears to optimise fuel use.

Beyond that, the Eco Elise is all about minimising environmental impact by the use of eco-friendly, even organic, construction materials. The hemp comes from fields close to the company's Hethel plant, the idea being that keeping it local reduces the carbon miles clocked up in transportation from afar.

The company has gone for solvent-free, water-based paint with a consistency consuming less energy than paints of old during its application. And the seats, as well as being moulded from hemp-reinforced plastic on the outside, are upholstered in undyed, biodegradable wool. Ditto the steering wheel boss and door trims.

The car also weighs in 32kg lighter than the standard donor car -- already a featherweight at 860kg. That's in part a by-product of the choice of build materials, but nearly half of the saving came from specially forged lightweight alloy wheels, which save 15.8kg.

Being lighter, the Eco Elise is both more fuel efficient and faster. It returned a combined 6.6L/100km, well up on the standard model's 8.3, especially considering it has the ability to hit 100km/h in 6.1sec.

Which hopefully doesn't open the way to a reprise the Cheech and Chong film's finest moment: when the van's rear end ignites under pressure of pursuit by a motorcycle cop. The Eco Elise is a one-off, but drivers fortunate enough to get a look in would be well advised to carry plenty of snack food with them in case they're pulled up.