Cars start decaying the moment they are built. Some manage to accumulate character while most don’t. What do you do?
One response is obsessive polishing and maintenance. The other is stoic acceptance. For many the response is to oscillate in between the two, starting with careful stewardship of the new possession. Why do people fight physics? And why is it that cars don’t last longer?
Every material has an inherent problem. That problem is that the material inevitably has a disadvantage. Compounding that is that entropy only increases though it locally can be reversed (while still increasing it in aggregate). So, engineers can only ever balance compromises when selecting materials. All of them will one day rust, break or dissolve or flow away.
The unfortunate thing with the failures of certain cars is that you don’t tend to see the trade-off. So, this small meditation on the characteristic ways vehicles decay is almost necessarily unbalanced. Who knows what useful feature of the 1993 Mondeo balances the propensity of its side-glass rubbers to curl where the meet at the B-pillar? Maybe the paint was a fraction thicker or the interior lamp just a shade more illuminating. The Volvo 240 tended to rust around the vent at the base of the rear-window. What advantage came of the fact Volvo never invested in a way to stop that?
In the last twenty years Alfa Romeo badges became more prone to flaking. Did someone invest the money saved in enamel in a better ink for the interior graphics? Renaults, as I like to say, have a strangely uniform failure rate so that everything seems to go wrong at once. And clearly no particular aspect of Renaults can make up for this fact. With a few exceptions, Renaults are uniformly mediocre cars but are demonstrable proof that good materials analysis can result in very carefully planned obsolescence.
The single heaviest material in a car is steel. The biggest advantage it has is that it’s cheap and plentiful. It isn’t actually the best material for the job but on balance it’s better than all the others. It’s main competitor is aluminium which is also lighter, plentiful but not nearly as cheap. It scores over steel in that it’s lighter but apart from that it comes with a host of disadvantages. People are aware it doesn’t rust which is what steel is known for. Thus, 120 years into the Car Epoch, we find most of a car’s body is still steel, prone as it is to oxidization. Steel versus aluminium characterises the general point about trade-offs and also about decay.
Around about now all the Mk1 Audi A8s are getting into the start of their second decade on the road. Famously made of aluminium, the Audi A8 weighed 200 kg less than an S-class of the same time. That figure is to be taken with a pinch of salt as the W-140 was enormous and the Audi less so. Key among the potential problems is that aluminium fatigues faster than steel as it’s more brittle. So, while the A8 is not visibly rusting, small cracks are propagating somewhere in its structure and we’ll be finding out where they are in due course.
As I mentioned elsewhere, plastic is taking up a larger proportion of non-load-bearing parts of cars but still hasn’t displaced glass except on a few racing cars. That’s because glass is harder. How does it decay? It tends to become crystalline when exposed to ionizing radiation which is why you should never park near plutonium or uranium. Glass flows slowly too. It doesn’t rust and can withstand extreme temperatures as well. Alas, it’s even more brittle than steel which is one reason we don’t have Lalique cars.
So back to plastic. It’s quite stable (perhaps too stable) but doesn’t like sunlight which breaks down the long-chain molecules that account for its flexibility. That explains the lightening of unpainted plastic parts on car exteriors. For many, the Opel Corsa B is synonymous with faded wheel arch trim and so too is the Ford Ka Mk1 which borrowed the theme and moved it on. Still, the parts don’t fail as such, they just look a bit grim. Another type of plastic, vinyl, we have discussed here but it’s worth recapping that in return for adding questionable style and reducing the need for paint, the vinyl roof served as a rust-trap and cracked with age.
It all wears out. Tyres harden, copper cables oxidises and crack, small connectors gradually dissolve in the hot, acidic, wet, dry, cold hell of the engine bay. Stress – I haven’t really dealt with this but from a stress-hinge on a cheap Mitsubishi to the flexure that causes cars (especially Renaults) to become loose and rattly – stress is everywhere acting on a car. So, even a car driven on dry, dust free roads of some motoring utopia would still begin to fall apart.
The decay of the materials of which the car is made is emblematic of the decay we are all subject to which is why I tend to view the fight against decay as a sublimated wish to deny mortality. The wish to buy a brand new car is another sublimation of this wish as well as the simple expression of the need to have a reliable, nice-looking vehicle. Interestingly, the more durable a car gets the less like an ordinary car it becomes. Grumman made a long-life vehicle for the US Post Office and it is incredibly durable but it also looks like it a train carriage; the Rolls-Royce Silver Shadow seems to go on indefinitely but cost five times the annual wage to buy and is so fabulously heavy it consumes petrol twice as fast as its typical contemporaries.
That said, both Volvo and Saab found methods to manufacture relatively affordable cars from quite normal materials: the 240 and 900 are virtually eternal cars, possibly more durable than the Silver Shadow and as durable as the W-123 Mercedes. That old car again – it too resisted rust and could enduring million-mile service. All three of our entropy resistant cars come from around the same time and it makes you think.
What if the secret of the everlasting car has been found and but for some minor revisions could still be made to work? It seems the trade-off for a durable car is in weight, adding a few percent extra seems to result in a profound lengthening of the service life. It also results in a trade-off you can feel, a lumbering quality that lends the cars a driving character nobody seems to like too much. Evidently, humans are not as rational as we would like since the wish for handling advantages is that we have chosen to have cars with a shorter lifespan.