Back to the drawing board: automotive inventions that never really took off

It’s been trial and error, with inventions such as New Zealander Alan Gibbs’ Aquada amphibious vehicle, four-wheel steering systems and seat belt airbags keeping designers busy.

Some models even came with illuminating tyres, built-in mini bars and a toilet to enable passengers to ‘go while on the go’. And while not all took hold, bold ideas are essential for progress to be made in the automotive world.

While the four-wheel steering system was designed to improve steering response and increase stability at higher speeds, it also improved turning and steering capacity at low speeds. Mazda adopted it early on, in its 1984 Mazda MX-02 concept car. The rear wheels counter-steered at lower speeds, making the vehicle very manoeuvrable. Honda, too, used it as an option in its Prelude and Ascot models from 1987 to 2001.

But four-wheel steering introduces greater complexity to the drive system, adding cost and weight which means increased fuel use. It’s still available in some high-end vehicles such as the Ferrari GTC4 Lusso and Lamborghini Aventador S Coupé, but those who spend much of their driving time sitting in traffic and on paved roads are probably better served in a car with traditional steering systems.

One of the most successful amphibious vehicle designs was the Amphicar produced in the 1960s. A 1.2-litre Triumph engine in the rear powered it; a transfer case facilitated switching power to two 12-inch propellers when the car entered the water. The Amphicar could cruise at eight knots, with the front wheels acting as rudders to steer it. But it was very slow on the road.

Years later, the Aquada was developed. It was a concept car with limited production and respectable speeds, being capable of 160km/h on land and 50km/h, or 27 knots on water. But the amphibious vehicle was not embraced, perhaps because of the exorbitant price tag. 

German engineer Felix Wankel came up with the Wankel rotary engine, first patented in 1929. The basic idea was to use a rotating design to convert pressure through a spinning motion. Rotary engines did offer benefits: a higher power-to-weight ratio than a piston engine and at a smaller size, and the ability to reach superior revolutions per minute, or RPM. On the flipside, they are poor on economy when running on conventional fuel and they produce high emissions.

Mazda is synonymous with the rotary engine, as showcased in its RX7 and RX8 models; there are rumours a RX9 is on the way. Apparently Mazda is also developing its rotary engine to use as a power plant for a range-extended electric vehicle.

Every modern car has seat belts and air bags; some have seat belt airbags. When they inflate in an accident, they help spread the force of impact. 

The technology was first offered in the 2011 Ford Explorer in North America and it proved popular: 40% of buyers chose the option. Some Ford Mondeos in Australia and New Zealand have inflatable seat belts that fully deploy down the length of the lower side of the seat belt, away from the face. Car manufacturers saw other safety technologies like Lane Keep Assist and Forward Collision Warning as more desirable – and comfortable – options to explore.

Concepts that didn’t originally catch on are sometimes given a second life. Electric vehicles were first invented in 1828. They didn’t gain the same traction as conventional internal combustion engines but over the last decade there has been rapid resurgence of that technology.

So, with that in mind, what will our roads look like in future?