Concepts and Prototypes : ALCAN/Austin Rover Aluminium Metro (1982)

The ALCAN/Austin Rover Aluminium Metro was an interesting project – it was a feasibility study into the full-scale production of a supermini in this lightweight material, as pushed for by BL Technology boss Spen King.

Although it wasn’t intended for production, it would have sired the alumiunium-bodied Austin AR6.

ALCAN/Austin Rover Aluminium Metro: A lesson in lightness

Following the success of the BL Technology-developed lightweight BL Technology ECV3 project, it was decided to evaluate a system of manufacturing for building aluminium structured vehicles and then test the structural integrity and durability. This Metro is one of six vehicles built as replicas of steel production vehicles, and employs the system of bonding panels, which has become more widespread in the industry.

Although the MG Metro pictured above looks completely standard, it has been constructed using these principles and, while there aren’t many miles on the clock, it’s weathered the years remarkably well. The entire structure has been bonded with Permabond adhesive – a system developed by ALCAN in conjunction with BL Technology – and all its panels are fashioned from aluminium.

Spen King oversaw its development, and was passionately in favour of lightweight construction – ultimately, though, cost and complexity meant that it was a system which wasn’t persevered with by BL.

Mastering the Permabond process

The techniques employed in the Permabond process.
The techniques employed in the Permabond process

In December 1982, this reseach was fully underway when the ECV3 was introduced, and while its aluminium structure was regarded as a flight of fancy by the press, the ASVT – Aluminium Structured Vehicle Technology system was pursued well into 1985, and was sold to the dealer network as the construction medium for the upcoming Austin AR6. However, with time, money and market share slipping, the outcome was inevitable: cancellation.

According to the book, Materials for Automobile Bodies by Geoff Davies, they were tested quite stringently – torsion, 1000-mile cobbled Belgian pave test, pothole braking, accelerated corrosion and finally the 30mph impact test. Given that the bare body in white weighs half that of its conventional pressed steel alternative, it’s a shame that the first supermini to employ these production methods was the loss-making Audi A2; a car that Spen King openly acknowledged to be the ‘son of ECV3’…

As far as British manufacture goes, it wasn’t until 2003, with the arrival of the Jaguar XJ (X350), that the results of this research bore fruit.

As always, if you know more, please get in touch or leave feedback below.

The Aluminium MG Metro survives at the Heritage Motor Centre at Gaydon.
The Aluminium MG Metro survives at the British Motor Museum at Gaydon
No clues here...
No clues here…
Keith Adams


  1. Did they ever collate any performance data on this car? It would be interesting to know how it compared in terms of 0-60mph time and top speed with the shell being so much lighter than the steel equivalent

  2. It was to me a sign of the back to front thinking in BL to put so much effort into doing a lightweight metro which was always going to be too expensive to make, while the Range Rover which could have used this technology to real advantage lumbered on with a ladder chassis and massive panel gaps.

  3. You need to be a rich and prosperous car company to dabble in aluminum construction for your cars, a cash strapped company should have stay with material it knows,

  4. Citroen looked into building the 2CV out of aluminium, but decided against when they found the cost of it compaired to still was about double, mostly due to the more energy used in the smelting.

    • The engineers on the 2CV could not master the welding techniques for alumiinum for production, this information ame from the Equinox docu8mentary anout the 2CV.

      Steel has many benefits, easily repaired, those “supermarket car park” dents can be easily fixed, not so with Aluminium, a slight knock causes the metal to stretch, very hard to panel beat back into shape again. I have owned an all aluminium car for many years, modern steels are so corrosion resistant, the advantages of aluminium over steel are not significant in the context of the motor car

    • Cost of Aluminium for the body of the 2CV was not too high and not the true reason for Citroen to abandon aluminium, recall the original Land Rover used alloy panels as there was Aluminium material spare post WW2 . In the Citroen 2CV documentary by Patrick Uden, Equinox “The Tin Snail” available on YouTube, the 2CV Engineers stated they could not master the Al welding process, the 2CV body entered production using steel.

  5. Obviously i didnt have an aluminium version, but the picture of the interior took me back to my MG Metro, RCU 52Y. Both the best and worst car I have ever owned. Nippy,stylish (I loved that chunky ssteering wheel!) and fun too, but in addition to being an unlucky car it had a shocking set of faults which cost me a fortune to repair. After a year off the road to replace the engine and front subfranme it was nicked.

    Regardless a great car, worthy of the metroname if not the MG badge. Always felt a fraud driving it as it was not a real MG but a great, great car. ( am i confused about this car or what!)

  6. To build an aluminium car the same way as a steel car means to waste a lot of the positive characteristics of aluminium. If pressed steel panels are simply replaced by pressed aluminium panels a lot of unneccessary material has to be used because aluminium is pretty soft. Therefore a car designed that way is unneccessarily heavy, just as Honca proved with their equally designed NSX.
    Properly done, an aluminium body would use extruded aluminium structures attached to cast nodes by glue, which make the best of the material’s characteristics and save a lot of weight. Just like an Elise or the respective Audis.
    To achieve this, it took a non-cash strapped company like Audi with their A8 D2, because you not only have to adapt existing production processes to a new material but to develop completely new production processes. I doubt whether a company as close to bankruptcy as AR would have been able to do this.

  7. And look how much money Audi lost on the A2….. i have one and its great but advances in steel technology are such the same car could now be built from steel at the same or even less weight. It will not however rust away….

    • The failure rate of the A2 body tub at manufacture was very high, it is believed at certain points of production to be 100%. such are the difficulties of forming Al into complex shapes

  8. Citroen & Panhard both did a lot of research in the 1930s & 40s on using aluminium for car bodywork.

    At the time the cost of suitable sheet aluminium was twice that of steel, due to the amount of energy need to produce it, especially in pre-nuclear power France.

    • Panhard’s Dyna X and early examples of the Z had a lot of aluminium in their bodies, but so of course did the Land-Rover.

  9. These days TATA – JLR are moving to an entirely aluminium parc. Just shows how far Charles Spencer King was ahead of the Game.

  10. Is it known what the weight of the existing Metro’s conventional pressed steel bare body in white was?

      • Even though an Aluminum Metro would have been very unlikely short of a thriving and well-capitalized BMC/BL/ARG deciding otherwise in limited-run A2 3-litre precursor form (possibly derived from a repurposed Metro as a city car carrying over elements of AR6).

        It is interesting nonetheless to compare the Metro’s lowest weight of 760kg with the similarly sized Honda Jazz’s (AA), Citroen AX and larger Nissan Micra K10 weights of 640kg, 640kg and 630kg respectively, seemingly without the extensive use of aluminum shown as shown on the ALCAN Metro.

        Apart from of course the aluminum/titanium-alloy head of the Jazz Turbo and fiber-reinforced aluminum alloy connecting rods on regular Jazz models as well as the engine in the Micra (with much of the low weight target for the latter appearing to largely entail a minimum of insulation).

        Even so it does bring up the question of whether the Metro could have had its weight reduced even further, the solution in the case of the AX was through extensive use of plastic panels in non-load bearing areas and varying the thicknesses of steel in the bodyshell to be the minimum needed to take required loads.

        • The AX was not a good example of lightness. It was a horrid car. My friend’s was uncomfortable and as soon as it hit 61mph it shook violently. It felt cheap and nasty.

          • Even so that is not to detract from other positive elements of the Citroen AX that could have been incorporated to the Metro such as its aerodynamics and lower friction engines, which were said to have been drawn from lessons in the Citroen ECO 2000 concept akin to how the AR6 drew upon lessons from the BL ECV3 concept (though neither the Clio nor the Twingo drew upon the lessons of the equivalent 1983 Renault Vesta / 1987 Renault Vesta II concepts).

            Furthermore regardless of how the weight reduction of the Metro is approached whether by aluminum (ALCAN Metro, AR6, A2), plastic panels (AX), minimum of insulation (Micra K10) or whatever solution was used for the Honda Jazz (AA) the result is pretty much a Metro with a kerb weight almost comparable to a Mini.

        • The heavy weight of the Metro is the iron A series engine and the front and rear subframes for the running gear, the other cars mentioned use the monocoque for the running gear. The Nissan Micra K11 rear axle assembly weighs about 20 kg, the Metro rear subframe assembly about 60kg

          • Understand the A-Series’s weight could have been reduced by the use of aluminum over the years from its development when alloy-heads were considered to attempts as all-alloy engines up to the alloy-head of the A-OHC prototype, also not sure whether the A-Plus was lighter compared to the A-Series (weight was removed from some parts and added to other parts of the engine) or if thin-wall casting was considered as a possible solution to lighten the engine.

            Is the figure for the rear axle assembly of the Micra for the later K11 or earlier K10?

            As for the weight of the Metro’s front and rear subframes, would it be correct to say the carry over nature of the car also accounts for the Metro’s heavy weight relative to its size compared to other similarly sized to larger rivals? Could the subframes have been lightened or possibly even deleted in better circumstances without having an overall negative impact on the Metro?

            Would the Metro’s increasingly niche gearbox have been another possible contributor to its relatively heavy weight?

  11. Galvanising steel is a cheaper alternative to making cars out of aluminium, and makes the body last a lot longer, as is substituting plastic for metal on some body areas. Fiat started galvanising their car bodies in the mid eighties, after developing a reputation for cars that rusted badly due to cheap steel, and largely beat their rust problem. Typically an early eighties Fiat Strada would need welding and Ziebarting by its first MOT, its successor, the Tipo, would rarely need any welding until it was 7 years old.

  12. Rover used aluminium on cars before the Metro, on the Rover P6 it was used for the bonnet and boot lid, from 1962/63 onwards.

  13. BMC looked at making an aluminium Austin A30/35, difficulty in pressing the panels knocked that one on the head.

    • It was also around that time when BMC first looked at making an all-alloy A-Series, though the fact it was still considered til the early-1960s via experimental Riley Elf equipped with such an an engine (that allegedly displaced around 998cc) suggests there were many attempts (even if the B-Series and C-Series could have benefited from all-alloy variants).

  14. Another BMC/BL/ARG/Whatever blind alley. It was 20 years before Jaguar managed to create a business case to build their flagship XJ out of aluminium, but ARG decided to throw god knows how much at alloy Metros that didn’t have a hope in hell of becoming a commercial reality. At this time that money would have been far better spent trying to stop the Maestro/Montego/Rover 800 from being the commercial disasters they where.

    • There was never a business case for aluminium bodied Jaguars. Ford pushed it on them. There were two reasons for this – firstly, to give Jaguar a USP in the market against Mercedes and BMW, and secondly, to keep a Ford owned aluminium plant open in Cleveland (Ohio).

  15. Yes, the Rover P6 had an aluminium boot and bonnet. Great watching the corrosion start around the bonnet badge and rear number plate and creep outward. No, aluminium does not rust but it corrodes.

  16. I dot think it was serious intention for a production Metro in aluminium, but as an exercise and assessment of aluminium fabrication techniques it makes sense, the Metro with its front and rear subframes as complete bolt-on assemblies for the running gear would be logical choice for such as exercise

  17. We have covered the topics of Aluminium, and conventional Steel for a car bodyshell.
    How about Stainless Steel?
    What are the pros and cons of fabricating a car bodyshell in Stainless Steel?
    Is it pressing difficulties of shaping panels and parts, or is it welding?

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