Tesla Cybertruck shocked the world. Whether you love or hate it, you cannot deny that it is one of those products that people are going to talk about for a while. It has a lot going for it, including the stainless steel body. It is nice to know that it won’t rust, but why all cars aren’t made from stainless steel?
Cybertruck’s exoskeleton is an unbelievably tough space-grade material, which resists hits from a sledgehammer. There is no denying that Ultra-Hard 30X Cold-Rolled stainless steel is one of the big advantages of Tesla’s pickup. Not only it is extremely durable, as demonstrated in that presentation, it also resists corrosion. This means that it doesn’t even have to be painted, if the buyer likes the look of raw stainless steel finish.
Stainless steel is an alloy of iron, carbon, chromium and some other elements. The more chromium it has, the more corrosion-resistant it is. Stainless steel was invented back in the 19th century, but it found its applications only from the beginning of the 20th century. Therefore, it is not new and it could have been used to make car bodies all along – so why our cars are still rusting?
Other cars with stainless steel bodies
Although stainless steel is not new, Tesla’s (actually, SpaceX’s) Ultra-Hard 30X Cold-Rolled is. It is a very tough and impact-resistant material. But we are talking about stainless steel in general, which was used to make cars before.
Ford has been experimenting with stainless steel bodies since 1930’s. Various sporadic tests and prototyping lasted till 1970’s but this work didn’t spawn any tremendous innovations in automotive bodywork technology. Meanwhile Cadillac Eldorado Brougham, made in 1957-1958, had a stainless steel roof. Maserati Bora from 1971-1978 also has this design feature. Although these manufacturers chose this material for aesthetic reasons, a shiny roof reflects sunlight better and does not allow for the interior to get as hot.
American and Canadian buses for decades had stainless steel bodies. Motor Coach Industries was making stainless steel buses until the later part of the previous century. But, of course, when you think of a stainless steel body, you immediately imagine the DMC DeLorean, made from 1981 till 1983.
None of the DeLoreans were painted – all of them came with a brushed raw stainless steel finish. However, some of the owners chose to paint their cars themselves, because after a while the stainless steel look kind of became boring.
There are more examples like that. When Porsche was making the original Cayman it couldn’t stamp the aft body panel from conventional mild steel – it kept cracking due to the many curves and angles of that part. And so Porsche opted for a more expensive stainless steel, which worked better in this application.
Why aren’t all cars made from stainless steel?
A car that doesn’t rust – isn’t that a dream? Maybe, but there are no stainless steel cars at the moment. Even the bodies of the DeLorean and the Cybertruck are technically not made from stainless steel, but covered in it. DeLorean’s stainless steel sheets were very thin, covering the real fibreglass structure underneath. And Tesla Cybertruck also has what is called “an exoskeleton” – stainless steel is only the outer skin.
That is because stainless steel is expensive and difficult to work with. If you looked at all of the mentioned examples, you would notice that all those stainless steel parts are very simple and flat, featuring just straight angles. Porsche Cayman is an exception – all other cars have very flat and very simple stainless steel parts. Even Tesla Cybertruck features simple straight lines and flat body panels. Stainless steel work hardens and that just makes manufacturing process just that little bit more challenging. It is also kind of difficult to weld, compared to a more friendly mild steel.
By the way, when DMC was making the DeLorean, they said that its body panels would never be repaired – if any damage occurred, they would be replaced. Again, because stainless steel is not easy to work with. Even the paint doesn’t stick to it too well.
Finally, why would you use stainless steel? To avoid corrosion? Other methods, such as using galvanization, high quality primers and paint, are good enough at preventing rust and do not cost as much. Remember that cars do not have to last forever, because people get bored from them and want something new once in a while. If manufacturers made cars that do not rust or break, pretty soon they would run out of business.
That, of course, doesn’t mean that Tesla is stupid and is making a mistake. Its stainless steel exoskeleton is a nice way to differentiate the Cybertruck from other machines on the road. And it is undeniably very tough. Who else can say that they have a car made from space-grade materials? That alone is worth the extra cost that goes into the making of Cybertruck’s exoskeleton.