That would be a lot of decades ago. Cars from the 80s routinely went well over 100k. The 70s cars I remember as more cantankerous but if taken good care of (which was simple because the cars were simple) they would as well.
Ironically, a hundred years from now I predict that the only working museum/collector cars left will be those from the 1990s and earlier. Newer cars will not survive as long, with all the fragile electronics that require maintenance with factory equipment that will no longer exist in a century.
What's more complicated about taking care of a car today?
Oil, oil filter, transmission fluid, air filter, maybe differential fluid, spark plugs. All cars today have these in fact cars today don't have distributor caps, spark plug wires, and power steering fluid.[3]
So what is more complicated about performing maintenance? How was it easier in the past? I can't think of a required maintenance task that exists now but didn't exist in the past and isn't a replacement for something.
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> Cars from the 80s routinely went well over 100k
That heavily depends on the brand. American cars were piles of garbage in my opinion and I'm sure I could find some source to support that. Here's a NY times article about how cars are now (in 2012) lasting more than 200k miles.
https://www.nytimes.com/2012/03/18/automobiles/as-cars-are-k...
My friend had a 91 Civic that lasted for about 250k but I had multiple GM cars (86 lesabre, 91 corsica, 88 6000) where either the transmission went or bent valves (exceeding the cost of the car) before 120k miles. Anecdotal but again Honda and Toyota were so popular the US government made Japan limit the number of cars coming in.[3]
https://www.latimes.com/archives/la-xpm-1987-01-28-fi-1076-s...
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Newer cars are less complex in key areas, including less maintenance [6]
- Spark plug wires are gone. Since they carried high voltage from the distributor cap they needed thick insulation and that insulation would crack due to heat cycling. once small cracks appear it would arc to the engine or other wires because of the high voltage. Now we have ignition coils which aren't considered a maintenance item (they last at least 100k but really more depending on use)
- No more distribution caps (due to ignition coils). Caps were a maintenance item
- No more power steering fluid and power steering pumps because of EPS racks. This also eliminates hydraulic lines
- Throttle by wire which eliminates the throttle cable that would get stretched out and sometimes break.
- In the past cars have timing belts, timing belts can break and if your engine was an interfere engine the valves will contact the piston causing a massive repair bill. Today almost every car has a timing chain which lasts significantly longer to the point where it's not a maintenance item.[1]
Starting the 80s we got OBD 1 then later 2 which provides sensor data. This allowed you to see the real symptom of the car instead of the apparent one. For example, car has a rough ideal but really it's running lean. Besides the massive performance and efficiency increase because the ignition timing can be based on the exhaust contents , temp, air flow levels, etc it also makes it easier to fix things by providing data on how the engine was operating. Today cars have even more computer diagnostic systems to help repair them.
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Finally let's get to the electronics you are concerned about. Cars now have more control modules, (which are mini computers for systems, like the door controls) then in the past. There's door modules[2], ambient lighting module, cruise control, etc. The point is you don't repair these modules you just replace them. You aren't soldering little resistors onto a board or something. It's no different than replacing a steering wheel. It's just a thing. [5]
Many of these modules are for optional luxury items. If 20 years from now the ambient lighting and module doesn't work in my car who cares. If lane assist, blind spot detection, or the rear camera breaks then the car is just like the older cars you think are better.
I'm sorry to make this accusation but you are probably letting nostalgia, the current climate of simmering anger at the world, and the desire for things you grew up with and are comfortable with to form your opinions.
I want to put a millennial into a muscle car from the 60s and they'll see the over boosted power steering, the giant v8 that was overrated in power and get 10mpg, a body that leans in every corner, tires that can't grip, and a chassis that feels like a rubber band when you turn. A modern 4 cylinder turbo hot hatch would destroy them and outlast them.
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[1] Some older cars had timing belts and non-interference engines. This means that if the belt broke the piston wouldn't contact the valves and the only repair you'd have to pay for is the timing belt and towing. Still annoying but better. Timing chains make more noise and because of their weight create more drag on the engine but with engine covers and the power today it doesn't matter
[2] In the past cars didn't have as many modules even for things like like power locks. Power locks used to just have control wires and power running directly to other parts of the car where relays might turn them on and off. The advantage of having a module is computer control. For example the following features are present on many new cars:
- lock the car when you start driving - unlock in park - windows up when rain is detected - auto down and up windows (all the way). - car can't go into drive when the door is open - specific door warnings (though old cars had a general one)
Doing all this by running wires around to other devices is insane so there's a module the window switches, lock switches, door sensor, door locks, window motor, and etc all connect to which then receives control info from other modules
[3] A few performance cars and maybe some older models of mass produced cars still use hydraulic steering.
[4] Mostly due to "perceptions" of American quality, small cars becoming popular, and the horrific engines in American cars in the late 70s and 80s as American manf had little experience with small engines that people wanted because of the gas crisis. There's also an emissions issue. American quality has somewhat equalized after the late 90s IMO
[5] Modules do need to be programmed with the config for your particular car. Buying one for your model and in your country usually means it's fine. There are also programmers that aren't expensive and dealers will often do it for a fee.
[6] I was also going to mention less oil changes but the argument there would have been massive. Oils are so much better than they've ever been that as long as you aren't burning it 10k / 1yr is probably for most people, 5k / 1yr for those that are worried.
You replace them if you can find a replacement. It's a lot harder to make ICs for outdated cars than mechanical parts for old cars, which was probably the OP's point.
Control modules are just software and you could probably make a generic one that takes different flashes with a variable pin layout, think raspberry pi.
This is done today to an extent with power upgrades. Take a look at a jb4 for a bmw b58. It intercepts data signals for different components, like the turbo, and changes values. It's just basic software.
That's not going to pass SMOG checks. It must be the factory control module, and it that's no longer in production, too bad.
For track cars it's fun to replace the electronics with customizable units, but you can't get away with that for a street car (in California at least).
Only cars prior to 1974 are not subject to smog check in California.
And part of the smog check is a visual inspection which will fail in the presence of any non-factory emission related equipment (such as engine control modules) even if their behavior is 100% identical to factory.
Electronics is what makes todays cars very difficult to repair down the road.
You're right in that when they are new it's actually easier to repair. Just plug in the diagnostic computer, it tells you what's wrong, you replace the whole module and done.
This gets very expensive though. For example I had a BMW with a brake light problem. In any old car that's a $0.25 bulb change, or worse case $10 in wiring if you need to replace all the wiring to it. Easy to do by anyone at home. On the BMW? It was a $1500 brake light control module that had to be programmed with a factory computer that only factory technicians have access to so on top I had to pay labor.
The real problems come when the cars get older. Any voltage variations from aging cables makes the whole system (everything is interlinked, unlike old cars) become very unpredictable. A friend is a BMW factory mechanic and the horror stories are endless.
As I noted in a peer comment, I had to sell for scrap a ~60K (when new) BMW that was mechanically and cosmetically perfect but had so many electronics glitches that it was impossible to repair without spending tens of thousands of dollars. What a waste. Such a problem is never possible with older cars, since the electrical system is simple and easy to diagnose and repair.
All the things you list as complex (spark plug wires, vacuum tubes, distributors, etc) are mechanically and electrically extremely simple devices. That's what makes repairs so easy at home without access to esoteric parts that might be out of production or factory tools not available to consumers.
No one is repairing an alternator, vacuum tube(what car has them), or a control module.