STORYTELLING fishermen across the world, prepare to hang up your hooks and rods because you will never top this one. The latest Mercedes-Benz concept car was caught swimming in a coral reef. That is a slight exaggeration, but then fishy stories always are. However, Mercedes’s extraordinary new Bionic Car really does owe its shape and much of its strength to a fish; not a streamlined shark or an elegant ray, but the chunky boxfish.

Bionics is all about combining biology with technology, so on one quiet Friday afternoon, Mercedes researchers were thumbing through the Wonder Book of Funny Fish when, on page 94, they saw the boxfish. At once they realised that within its cubic frame was the secret of tomorrow’s car.

The tropical boxfish may not look the sleekest or sexiest of piscatorial creatures, but the Mercedes team knew better. In fact, the boxfish is extremely hydrodynamically efficient and that meant it would be aerodynamically efficient, too, they decided — just what was needed for a car.

Unlikely though it may seem, they also discovered that its rectangular anatomy was almost identical to the cross-section of a car’s body and, because it has to cope with a tough natural environment — jagged coral and predators attacking without warning — it had a lot more in common with cars. It is able to protect its body in collisions, withstand high pressures, move with low energy consumption but plenty of power when needed and has good manoeuvrability. It also has a rigid skin with interlinked hexagonal plates to give maximum strength for minimal weight.

Transferred to the external panels of a car door, this system produces a honeycomb pattern, with up to 40 per cent more rigidity. Apply it to an entire car and weight could be cut by 30 per cent, yet crash safety and driving dynamics would still be excellent: nature had NCAP safety tests sussed aeons before the modern car industry. “There you are,” the Mercedes team chorused, “it’s a fish that thinks it ’s a car. It just needs four wheels.”

So they went ahead and built the boxfish car, although the marketing people decided that Bionic Car sounded better. A four-seat hatchback with a diesel engine and chassis from the Mercedes A-Class, it drives like a conventional car. It is roomy, with a huge glass windscreen extending into the roof. It has lively performance, a top speed of about 120mph and average fuel consumption of almost 66 miles to the gallon.

Like some cars, though, the boxfish has a bit of an antisocial emission problem, being able to eject a toxin sufficiently powerful to kill some fish. Not wishing to emulate that, Mercedes has given the Bionic Car a super-clean exhaust system, using a new fluid called AdBlue, to cut by about 80 per cent the nitrogen oxides produced by the diesel engine.

Although it is not as slippery as the boxfish, the Bionic Car is remarkably aerodynamic — about a fifth better than the slipperiest production cars. The problem, though, is that no matter how much you may like fish, the efficient, clean-living concept car does look odd. And clever though its design may be, will many people really want to buy a fish on wheels?

Professor Herbert Kohler, the director of vehicle body and drive research at Mercedes’s parent company, DaimlerChrysler, believes that aerodynamics will remain an essential element of design, despite the slowing effect of traffic densities and speed cameras. But styling will still be affected, he said, so car buyers may have to change their attitudes and accept what today may be seen as unusual or even weird — such as the Bionic Car.

Across Germany from Mercedes’s Stuttgart headquarters, Volkswagen are also bracing themselves for an outbreak of cars that swap pretty for fishy. Professor Wilfried Bockelmann, Volkswagen’s director of research, said: “At high speeds, aerodynamic efficiency is important, but on average, speeds are becoming lower and lower due to regulations and traffic density and I foresee more speed limits.

Styling may also be affected by the need to design in pedestrian safety. As a result, cars may not be as attractive — as elegant — as they are today.”

Which means that the not quite so elegant boxfish could be about to have its day, not in the ocean, but on the stormy seas of the world’s car markets. It might not be pretty, but it seems to work and that could mean that traditional car design, thanks to the humble boxfish, has had its chips.

INTELLIGENT ECONOMY DRIVE

FISH do not provide the only inspiration for designers searching for solutions. With environmentalists getting in a lather over motorists who drive too fast and, therefore, use more fuel, Volkswagen have shown that economy and speed can go together.

Volkswagen reckons that its EcoRacer can sprint from standstill to 62mph in 6.3sec and on to a top speed of 143mph yet still return more than 80 miles to the gallon. The car has a 1.5-litre advanced technology diesel engine, producing about 140 horsepower, centrally mounted in a carbon-fibre body. The prototype is to serve as a technology test bed. No details yet about possible production — but something like it is possible.