Axon's Automotive Anorak: Blind Alley Engineering

After Citroen making such a huge fuss over its clever Airbump innovation when the C4 Cactus was first launched in 2014, it seems odd and a backwards step that a mere four years later Citroen had removed this prominent feature and consigned this new ‘invention’ to the same skip as its truly pioneering height-adjustable hydrolastic air suspension, invented by the French marque in the early 1950s. 

This ingenious technology is just another example of a raft of innovative automotive ‘blind alley’ engineering that gets quickly and quietly dropped when either better and/or more cost-effective solutions come along.  

Here are a handful of other blind alley engineering ideas that failed to succeed; some well-considered, and others rather less so;

1 - Audi procon-ten

At first glance, Audi’s unique mid-1980s procon-ten system seemed like a clever safety solution to violent frontal impacts.

Developed by Audi as a propriety alternative Safety Restraint System (SRS) to airbags, procon-ten (all in lower case, as so strangely beloved by Audi, as with its quattro) was a safety device intended to create more driver survival space in a car’s interior in the advent of a front impact. 

The procon-ten system featured on selected Audi 80, 100 and 200 models from 1986 onwards, yet this clever but complex and costly system lasted less than a decade, with Audi accepting defeat and adopting SRS airbags by the mid-1990s, in-line with all of its competitors. 

Audi’s procon-ten used winch-like cables running around the rear of the engine. In the event of a frontal collision, the impact force and momentum would shift the engine rearwards, tensioning and 'pulling' the cables, which were in turn connected to the steering column and seat belt mounts.

When the Audi’s cable was pulled tight by the engine, the cables would pull the steering wheel away towards the front of the car, and in principal, clear of the driver. In reality, however, real-world customer results soon revealed that in the event of an imminent impact, drivers would naturally grip onto the steering wheel hard, sometimes resulting in the motorists’ arms being pulled out of their sockets by the procon-ten system as they clung onto the steering wheel for dear life. Ouch!

Unsurprisingly, various lawsuit claims ensued, particularly in the United States where Audi was only just recovering from a damaging and costly ‘unintended acceleration’ problem with its automatic models, which destroyed the Brand’s reputation there for many years. Audi unceremoniously dropped procon-ten and introduced more effective airbags as its SRS system, in-line with the rest of the motor industry by the mid-1990s.

2 - NSU Wankel Rotary Engines

Bavarian motorcycle and city car maker NSU let ambition got the better of it in the early 1960s when it introduced its nifty Bertone-styled Spider. A charming little two-seater drophead, NSU’s 1964 Spider claims the dubious distinction of being the first production car in the world to feature a rotary engine, developed by German engineer Felix Wankel.

Using Wankel’s innovative water-cooled single rotor engine of a notional 500cc, the NSU’s motor had a quasi-oval design of the combustion chamber, containing a three-part rotor within the chamber that enabled the combustion pressure to be converted directly into a rotary motion. 

There was no loss of energy to convert the reciprocating movement into rotational movement, resulting in a compact, free-revving engine which was hailed by many at the time to be the next major step forward in automotive design.

It was later found that the characteristics of critical materials selected and applied by NSU to build production Wankel engines were inappropriate to the stresses they would bear, and rotary-engined cars soon earned a reputation for unreliability, this coming to the fore with the advanced, but far too ambitious, NSU Ro80 executive saloon of 1967. Not only was NSU’s basic dealer network not used to dealing with such an advanced technical tour de force as the twin-rotor 1-litre Ro80, its fast-wearing rotors proved to be a technical nightmare. 

NSU’s Wankel engines required frequent rebuilding to replace worn apex seals, resulting in spiraling warranty costs associated with the installation of a second, third and even forth rotary engine in failed, low mileage Ro80s. These problems quickly destroyed NSU’s financial viability and the Ro80’s status, ultimately forcing a merger with Audi as part of the expanding Volkswagen Group in 1969. 

Citroen briefly dabbled with Wankel engines in the early 1970s, but the Fuel Crisis soon put paid to these thirsty motors, leaving just Mazda to persevere with the Wankel; the Japanese brand resolving the engine’s reliability and longevity issues through sharper quality controls. High fuel and oil consumption always remained a challenge with the smooth, high-revving rotary engines though. Today, no Wankel engines are used in mainstream vehicle production, although Mazda may change this situation soon if motor industry rumours are to be believe by reviving rotary power.

3 - Studebaker Lark Wagonaire Sliding Roof

In the dying days of the once mighty Studebaker marque, this American car maker introduced a logical innovation on its Wagonaire station wagon models; a sliding roof over the rear cargo zone to usefully expand the luggage area upwards to infinity and beyond. 

Between the 1963 and (sadly final) 1966 Model Years, all Lark-derived Wagonaire estates included the simple but versatile sliding roof, which would be left closed for normal use, but could be partially, or fully, slide back for use as a viewing base for the Studebaker’s occupants, or a platform to transport long and awkward items, such as a ladder or wardrobe. The Wagonaire even thoughtfully included a fold-down step, built into its drop-down tailgate, to facilitate passengers climbing onto the Studebaker’s viewing platform. Most ingenious.

The light box van variants of the Renault R4 (and later R5 Express) took a leaf out of the Wagonaire’s roof by incorporating a clever little opening flap above the rear door to poke long items through, but it wasn’t quite as commodious or versatile as the simple Studebaker solution. Astonishingly, in this age of SUVs and crossover vehicles, no other carmaker has yet to capitalize on Studebaker’s foresight of almost 60 years ago and offer a practical sliding roof as a handy selling feature for their dreary family cars.  

4 - Mercedes-Benz A-Class ‘Sandwich Bar’ Packaging

When Mercedes-Benz introduced its first ‘mini’ front-wheel-drive model, the W168-series A-Class of 1997, the Stuttgart Company didn’t slavishly follow the well-worn solution of a classic two-box hatchback, as used with much success for the VW Golf, Vauxhall Astra, and so on. No, its engineers were brave, bold and radical, choosing to adopt a clean and modern mono-box profile with a high roof, upright seating and clever, efficient packaging. 

This not only made the original A-Class uncommonly spacious and practical for its compact dimensions, but also enabled exceptional all-round visibility from within the cabin, plus give a distinctive high-riding profile in traffic. 

A key innovation of this first true compact Mercedes was a cunning frontal-impact absorption system known as the ‘Sandwich Bar.’ In the event of a major frontal impact, the engine and transmission were designed to slide underneath the floor of the car and pedals, rather than entering the passenger compartment.

This was a major safety advance, but one sadly blighted by the model’s top-heavy body, which soon after public launched proved to be too unstable in violent maneuvers, the mini Mercedes rolling over in the famous Swedish ‘moose test’ to avoid an elk; a common cause of road accidents in Scandinavia.

Mercedes initially denied this problem, but then took the surprising step of recalling all 2,600 units sold to date and suspending sales for three months until the problem was solved by adding an electronic stability control system and modifying the suspension. Mercdes-Benz spent DM 2.5 billion in developing the A-Class at the time, with a further DM 300 million spent to fix it!

Later A-Class models disappointedly followed the mainstream herd with a more conventional lower height two-box shape, giving far less efficient packaging.

5 - Renault 17 Petal Seats

6 – Chrysler Turbine Car

In the optimistic ‘jet age’ of the early post-war 1950s, a number of car companies (including Fiat, General Motors, Renault and Rover) developed and demonstrated dramatic gas turbine-powered prototypes.

Rover’s P4-based ‘JET 1’ of 1950, for example, set a speed record for a jet turbine car in Belgium in 1952, where it achieved an impressive 150mph. Rover went on to develop this engine technology well into the 1960s, with its Rover-BRM competition racer competing in the Le Mans 24 Heures race in a special ‘experimental’ class with Grand Prix World Champion Graham Hill behind the wheel in 1963 and ’64, and joined by Jackie Stewart for 1965.

Chrysler went one step further by putting its Turbine Car into very limited production (just 55 units) between 1963 and ’64 to research gas turbine use on the road. The Turbine Car could operate on many different fuels, requiring less maintenance and lasting longer than conventional piston engines, although the jet engines were much more expensive to produce.

After its own in-house testing, Chrysler conducted a user programme from October 1963 to January 1966 that involved 203 individual drivers in 133 different cities across the United States, cumulatively driving more than one million miles.

This programme helped Chrysler to determine a variety of problems with the gas turbine cars, notably their complicated starting procedure, unremarkable acceleration, poor fuel economy and high noise levels. Chrysler’s experience also revealed key advantages of the turbine engine though, including remarkable durability, smooth operation, and relatively modest maintenance requirements. After the conclusion of the user programme in 1966, Chrysler reclaimed all 55 Turbine Cars and destroyed all but nine of them.

Turbine engines then lay dormant for some years, until Toyota revived the technology for car use with its 1987 GTV (Gas Turbine Vehicle) concept coupe. The GTV used Toyota’s Gas Turbine II engine, with a one-stage turbine used to drive the compressor while a second turbine was connected to the drive shaft. The second stage also took the place of the fluid flywheel (torque converter). Low-scale GTV production was planned, but this never materialised and Toyota lost interest in gas turbine motive power, along with the rest of the motor industry.

7 - Fiat Panda Hammock Seats

When the original Ital Design Fiat Panda first revealed its friendly face 40 years ago, one of the stand-out features of this cute city car was its remarkable hammock-type seats.

Practical and functional, the Panda’s unusual thin seats resembled wafer biscuits, but added a degree of versatility rarely seen in any other car before or since. 

Not only could the Fiat’s fabric seat materials (and dash covering) be removed and machine washed, but the rear seat could be totally removed, and/or placed in various positions to act as a V-shaped hammock to safely store luggage and prevent it from rolling forward, along with babies, pets and all manner of items. The front and rear seats could also simply be folded flat to create a double bed (as could the earlier Saab 96, Renault R16 and Austin Maxi).

A masterclass in functional simplicity, the 1980 Panda took its inspiration from the rustic Citroen 2CV and Renault R4, but in a more modern and compact package. Created by Giorgetto Giugiaro – the most celebrated vehicle designer of the 20^th Century – the original Fiat Panda remains the stylist’s most proud work, his favourite car to come from his own pen that also styled everything from the first VW Golf and Alfasud, through to the Lotus Elite and Maserati Bora. The inspired hammock seating was his idea, for which he’s justifiably proud.

Although hammock car seating died with the first-generation Fiat Panda, a wide range of hammock accessories are now available to pop your pet pouch into!

8 - Honda CR-V Shower

When following an original 1996-2001 Honda CR-V, have you ever wondered what that strange removable panel on the bottom left of the tailgate is for? No! Well here’s the answer.

When Honda took its first foray into the ever-expanding 4x4 SUV market in 1996, its Mark 1 CR-V included a handful of useful features that the true off-roader might find of use such as extra interior grab handles.

One of these was an amusing but useful option; a shower attachment mounted on the swing-out tailgate with a water bottle slot in the rear boot side compartment, hence that odd removeable panel to drain unused water from. After a muddy cross country run or a tiring mountain bike ride, the CR-V’s shower attachment could not only rinse off the exhausted athlete, but also hose down their sports equipment.

Pre-war, running water and a fold-away wash basin was a popular option on an expensive coachbuilt limousine, enabling the chauffeur to wash oil and grease from his hands. Horch even created a storage facility for a sink and taps in the front wing of its short-lived 1939 930 S, with a towel rail at the back of the front seats!

More recently, Nissan has offered an accessory pack for dog-loving X-Trail owners, including a small shower pump and nozzle to wash their paws, as well as a special dog mattress that repels fur.

9 – Austin Allegro Quartic Steering Wheel

Our final example of dead-end engineering is arguably one of the most well-known and pointless, the famous Quartic steering wheel, a much-storied gimmick seen on the original Series 1 Austin Allegro models at launch in 1973. 

A rectangular oval, rather than the more conventional round shape, the Allegro’s Quartic steering wheel was said to increase cabin space and knee room for the Austin’s unfortunate driver. This of course was utter drivel as the motorist would have less knee room when the wheel was turned! Still, it had the desired effect for British Leyland initially as this odd wheel helped to create miles of column inches about Austin’s new hope of 1973. The Quartic wheel was soon dropped due to owner complaints, however, even before the Series 2 Allegro models were introduced in 1975.

The infamous Allegro wasn’t the first car to feature a misshapen oval steering wheel – adventurous Chrysler introduced an oval wheel for its wild Virgil Exner-styled 1961 Model Year Imperial models, plus the Plymouth Fury and 1962 Chryslers.