Aerodynamics: The Shape We’re In

We ask whether aerodynamics’ post-war, post-aviation beginnings have anything in common with tomorrow’s hydrogen-powered wonders.

The future? Volkswagen-xl1-photo via motortrend
The future? Volkswagen XL-1. Image: Motor Trend

Car manufacturers have historically enjoyed a somewhat patchy relationship with the concept of aerodynamic theory. During the post-war period only a handful of motor manufacturers paid more than lip service and of those, most had their origins in aircraft manufacture. Bristol and Saab, for example were both forced to diversify during post-war austerity when demand for their mainstay aircraft businesses collapsed in peacetime.

Having only 2-litre engines, Bristol’s 401-405 series were overtly streamlined, their shapes optimised to counter a lack of engine displacement. Bristol’s aerodynamic studies reached its apogee with the advanced 450 Le Mans race cars, a design that turned the whole ‘if it looks right, it is right’ adage on its head.

Bristol 450 Le Mans - photo via toplowridersites
Slippery when wet – Bristol 450. Image: Toplowridersites

Aviation practice also informed the 1949 Saab 92, a lightweight, compact and slippery body powered by a small-displacement two stroke engine. Panhard enjoyed fewer overt aviation associations, yet their 1954 Dyna Z had even more in common with aircraft practice, featuring a streamlined aluminium monocoque body. Both embodied a futuristic if unorthodox approach to the mass-market compact car. But the fact that none of these manufacturers exist today says volumes about the cost of remaining true to one’s ideals – aerodynamic or commercial.

1954 Panhard-Dyna-Z - photo via carpictures
1954 Panhard-Dyna-Z – photo: carpictures

Citroën’s André Lefèbvre began his career working for aviation pioneer, Gabriel Voisin before switching to automobiles. This background inspired a series of advanced cars which embodied aircraft principles – notably light weight, wind-cleaving shapes and in some models, the use of powered hydraulics. Lefèbvre was the progenitor for generations of ultra-aerodynamic Citroëns, a legacy which has probably been unsurpassed amongst mainstream manufacturers, for all the good it’s done them.

Italian carrozzerie Bertone and Pininfarina also embarked upon aerodynamic studies throughout the 1950’s, the highlights of which were Bertone’s BAT-series of Alfa Romeo design studies. Pininfarina’s work in the field was mainly geared towards aesthetics, although their 1968 Berlina Aerodynamica concept would come to dominate early 1970s saloon design. Their research would lead them to construct their own full-sized wind tunnel in 1972 and the groundbreaking 1978 CNF-PF concept, a saloon shape that adhered to the purest aero form possible and frankly isn’t too far removed from today’s ideal either.

Pininfarina Studio CNR aerodynamic concept - photo via
Pininfarina Studio CNR aerodynamic concept. Image:

The after effects of the 1973 oil shock caught everyone off-guard, with previously apathetic car manufacturers forced to re-assess their business models and with the emphasis moving decisively towards efficiency, aerodynamics took on an importance that had hitherto eluded it. With everyone using wind tunnels, manufacturers realised that fuel-efficient drivetrains and air cleaving lines weren’t enough. Cars didn’t just need to be aerodynamic, they had to look it.

The 1981 Audi 100 took this to its logical extreme, proclaiming its wind-cheating capabilities with the cd figure stencilled on the rear three-quarter glass. Today, the use of sophisticated computer modelling allows even quite conventional looking designs to achieve figures previously the preserve of overt streamliners, but the status-‘quo-efficent’ is not likely to remain for much longer.

1980 Opel Tech 1 concept - photo via gmeuropearchive
1980 Opel Tech 1 concept. Image: GMeuropearchive

With the legislators now looking to slash emissions dramatically, another major push is likely. Further to this are developments in alternative propulsion with areas like rolling resistance and drag reduction coming under renewed scrutiny. There is a growing belief that for cars to achieve drastically lower drag coefficients, shapes will have to become more harmonised and details like semi-enclosed wheels, air-tunnels, movable aerodynamic devices and the removal of a good deal of outer addenda will become necessary. Some observers worry that we could see a similar harmonisation that has made commercial aircraft virtually indistinguishable from one another – or to put it in simplistic terms, everything could end up looking vaguely like a Prius.

Nostril alert! Toyota's visually challenging hydrogen-powered Mirai.
Nostril alert! A possible future embodied in Toyota’s hydrogen-powered Mirai.

The potential advent of hydrogen power may prefigure a further stylistic shift. Toyota’s recently announced Mirai is reputed to look the way it does, not as some assert because Toyota’s design team were ingesting heroic quantities of crystal meth, but due to the drivetrain’s need for large quantities of cooling air. Should hydrogen cars become the norm, designers could find themselves facing sterner challenges moulding engineering necessity into showroom appeal.

Aerodynamic air channels on BMW’s i8. Image: uncredited

It’s worth remembering that aerodynamics’ early adopters embraced the science largely through expediency. While many possessed the skill set through an aviation heritage, all were united in the need to make small capacity engines go further and faster. We face similar challenges now. As engines look set to become mere generators and capacities are slashed, getting more from less seems likely to once again drive the agenda. Perhaps Saab and Panhard were right all along.

Aerodynamics are once again moving to the forefront of car design. However, those of us who value styling diversity may find ourselves having less to celebrate in the years to come.

Author: Eóin Doyle

Co-Founder. Editor. Content Provider.

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