The Square Wheeled Imp!

Take a look at the publicity shot for the Hillman Imp. Notice anything different about it? No? Well you’re not looking hard enough…

Back in the 1960s and 1970s, design for cars was both innovative, and yet also sometimes down some blind alleys. The Wankel rotary engine was a revelation in terms of refinement, but in the NSU Ro80, the warranty claims ended up bankrupting the company. British Leyland, meanwhile, pioneered the quartic steering wheel in the Austin Allegro. There were also somewhat unsuccessful attempts at electric power from the likes of Enfield.

Innovation

In a small corner of Ryton, the Rootes Group were also attempting innovation. Not content with putting their engine in the back of the Imp and creating an opening hatch, they also turned their attention to ways of making their new small car more economical. One idea which progressed almost to production was the square wheel. The idea was that the wheel would be in contact with the ground less than a round one, and so there would be less friction, thus making the engine more efficient in how it powered the car. Initial tests were indeed promising, and one tester reported fuel economy of 90mpg. Such returns were not to be sniffed at!

The company redoubled their efforts, and sent some cars on trial to the Alps, to see the affect at high altitude. This was also so successful that Dunlop were asked to tool up for mass production of the square tyre to go on the square wheel.

A small problem

Shortly before production however, the idea was canned. Senior management were uncomfortable with the affect on the ride quality, which was reported to be akin to driving up and down stairs. Whilst the Imp was a small car, and by definition utilitarian, this was considered a step too far.

So it was that another British innovation bit the dust, leaving only pictures such as this rarity surviving. It may not be obvious from the photo, but I’m sure if you look carefully you can see the different shape of the wheel.

Another ‘what if’ for the British Motor industry?