My main concern is the same as with electronic gear levers/selectors, electric parking brakes, steer by wire, and throttle by wire:

What happens when the car has a failure that kills all the electrics?

That's a much more common failure scenario than people think. Batteries go flat. Wiring gets chewed and shorts with vibration. CAN buses need only a brief short to go out entirely and not reset. Even in a modest crash the car can lose its battery and alternator, or get a system short.

Tesla owners have learned this lesson repeatedly with getting locked out, locked in, stuck in park, unable to shift to neutral for a tow, etc. Other car owners have learned this with electric parking brakes getting stuck on.

If the electrics fail and the car is moving, I need steering, brakes, and the gear lever to all work to stop safely. If they're by-wire, I'm just a passenger.

Same thing that happens if a brake line pops, steering wheel locks up, or the throttle gets jammed open. There are ways of designing redundancies into those systems. Multiple communication channels, reserve sources of power. A lot of new model vehicles already have this stuff, drive by wire for example has pretty much been the standard for twenty years now. Typically, the entire system doesn't go down because they're designed for that not to happen.

But I'll take my mechanical overrides.

My one-off experience. Parked my car once for a long holiday (two months). Mice chew through the main wiring loom behind the dashboard and urinated over electronics (urine is slightly corrosive). 1) no mechanic has time to repair single wires 2) dashboard removal is more than day of labor 3) main can bus failures are hard to find and require pulling modules till canbus high/low get the right voltages I’d say a hard NO towards flybywire brakes.

Don't forget the possibility of adding digital locks so it can only be serviced with authorized parts by authorized dealers "for your security and safety".

Also, these systems are much more difficult to diagnose if they fail to function correctly. This means you are going to pay for 5 different things to be replaced, each after replacing the previous one didn't fix the issue. And you are going to pay big time for every replacement.

Not really. The issue with modern automobiles they don't really report much useful information about themselves beyond general upstream faults. One issue can flag errors in five modules, and it depends on the tech to know about the underlying technology in addition to diagnosing whatever mechanical issue. Techs also tend to be the type of people to throw up their hands and start throwing parts.

This is kinda where we need to shift more towards EVs because that would take out a lot of the complexity you get with modern automobile design.

> and it depends on the tech to know about the underlying technology in addition to diagnosing whatever mechanical issue. Techs also tend to be the type of people to throw up their hands and start throwing parts.

What do you think how well documented car internals are? What would you do if you open a control device and you see an unmarked ASIC?

It depends on the manufacturer. Some are better than others. Some document pretty well but are overshadowed by crap manufacturing.

Personally I really like how Tesla did their online service manual. It's a good balance of technical but not to technical.

https://service.tesla.com/docs/Model3/ServiceManual/en-us/in...

With regard to your edit. That's where there's a practical limit of what do you (a manufacturer) publish that the tech needs to know. So you need to cross it between technical know how, and how detailed you need to get. Me personally would pull out the oscilloscope and make some probes to get an idea of what to do. You set a carburetor on my desk and that would probably take me a bit longer over electronics. It's a skillset issue, basically, and we're transitioning off strictly mechanics to mechanics and electronics working together. Which naturally raises labor costs because people aren't use to that.

Not sure if my point came across. This is a knowledge problem. How can you test an ASIC for correct function if you have no knowledge of its intended function?

Right. That's what I added. You have to reverse engineer what's going on. As with anything if you don't know how it works. If your IC is producing crazy readings, or you look under a thermal camera, probably can blame the chip. Good luck getting a replacement.

Some of these sound like upsides to me. I've owned a lot of older cars, and they're always a mystery box of "what will fail next?". So many moving parts, and they're often hard to diagnose.

Based on your comment, I expect newer cars to have lower maintenance and repair costs, fewer part failures, and less guessing about exactly which part is broken.

There is the crux:

> while electronic systems come with components that are replaced wholesale, where the consumer pays the price for the new component

Repair costs are skyrocketing with newer cars.

Off the cuff, I'd say at least half of my repair costs are the labor. Any chance you've seen figures on how much more expensive the parts are for newer cars?

It has to do with modularity and commoditization. Modern parts can be highly integrated and digitally customized to specific applications, in such a way that they become increasingly scarce and eventually impossible to find, whereas older cars are mostly made from commodity components where the same part is interchangeably used in tens or hundreds of vehicle models, and many become cheaper and easier to obtain as time goes on and tooling costs are amortized over decades.

Its not just the replacement parts cost. Modern cars are more tightly packed and not designed for individual parts being replaced afterwards. Sometimes its just things like a screw holding something behind the center console being accessible from the engine compartment in a position that forces a full engine/transmission removal. These are tiny things but can turn a 30 minute job into two person days.

Or a oil pipework that cannot be removed from the engine because there is a bracket in the way, which can only be removed by taking out the the master brake cylinder, which requires the brake pedal to be loosened. The brake pedal braket is mounted by 4 screws, one is only accessible by removing the cladding behind the steering wheel, the steering wheel blocks that, so you have to take that off, too.

.. fixing cars is a special kind of hell.

Newer cars do have lower maintenance and repair costs. This is why vehicles with over 100k miles still fetch a fair amount of money. Computers are very good at doing the same thing over again indefinitely, unlike fully mechanical implementations which tend to drift out of spec slowly over time. A side effect of that is they require more time to actually get in and fix things.

Unlike older cars, the way newer cars work is shielded within software and hardware black boxes and aren't particularly modular. You can't just pull a carburetor out of one car and put it in another. And you're fully dependent on the manufacturer to publish meaningful diagnostic information.

> this type of complexity tends to have a more favorable profile for economies of scale

Yeah, but what about economy of safety?