Any American owners of Toyota Prius out there?

[CaptainBeowulf]

In some ways I think the core failure is that our cars have become too populated with electronic gizmos we don't need which increase possible failure modes. In one major respect, modern cars are significantly less safe than old ones - if you break down in a remote area, you can't fix the dang thing anymore.

Of course, computer controlled engine timings, fuel injector rails, direct injection... they all give you a massive boost in fuel economy - and there's probably not an efficient way to do a hybrid like the Prius without letting the computers control the different systems. So you have a tradeoff.

But does anyone here use cruise control? I don't think I've ever used it on my current car... in fact, if I could a buy a car without it, I probably would. I don't feel fully in control of the vehicle with cruise control on.

These problems are likely to only get worse... you're now getting cars with automatic adaptive cruise control and braking if the car thinks it sees another car or a pedestrian ahead. See, for instance, some new Volvo models. I'm just waiting for the first time one of these vehicles' computers glitches and "thinks" it sees a reason to stop in heavy high speed traffic, slams on the anchors, and causes a pile-up.

Also, the problem crosses over with the insurance discussion from the other thread. People can think "I'm insured" and they can think "oh, I don't have to pay attention, my car will stop for me." Now I agree that everyone should have insurance, but the sum total of too much of this stuff is to encourage lazy driving... kind of like the nanny state installed into automobiles.

[Tom Ligon]

The "Emergency Brake" is nothing of the sort. It is a parking brake. On most vehicles it sets one of the rear brake shoes on each rear wheel. That's typically less than 1/4 of your total stopping power, assuming it would apply maximum force.

I'm sorely tempted to write a short SF story extrapolating this trend, but I don't think much extrapolation os necessary. Yes, we've gizmoed up cars with one safety feature on top of another to the point that the antilock brakes won't let us slow down a runaway engine, and yes, I do expect the hazard detection system will cause accidents.

The basic theme of the story comes from the nursery rhyme, "There was an old woman who swallowed a fly ..."

http://www.poppyfields.net/poppy/songs/oldwoman.html

[chrismb]

Of course, computer controlled engine timings, fuel injector rails, direct injection... they all give you a massive boost in fuel economy - and there's probably not an efficient way to do a hybrid like the Prius without letting the computers control the different systems. So you have a tradeoff.

I had a Austin Rover Maestro diesel. Those who know UK cars won't be impressed by that, but that Maestro was the second direct injection diesel engined car ever to be sold (the first was a car called the Fiat Tempra) and it did it with a mechanical pump and normal aspiration. And it gave >60mpg. Not a computer nor high tech turbo nor EGR insight. Such cars have become completely worthless over time so 99.9% are scrap, so the answer to your point is - there may be no efficient ways to be as efficient as a Prius without computer murlarky any more.

[Maui]

I have a Prius (2006).

My understanding is that the recent runaway prius was stopped by turning off the car. Also, I understand putting it into neutral is a fail-safe way to stop any car (the driver of the recent runaway Prius claims he was afraid it would flip if it did that-- I think there's a 50% chance this guy is full of it and is trying to take advantage of the situation)

I actually was in a low speed accident this summer that I believe was at least partially to blame on a brake problem (I posted about it here)

My opinion is that there is a software issue, and the electronics are taking away direct control to the point of being dangerous.

Still, as much as people will probably laugh at the statement, we still love the car.
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[chrismb]

I actually was in a low speed accident this summer that I believe was at least partially to blame on a brake problem (I posted about it here)
My opinion is that there is a software issue, and the electronics are taking away direct control to the point of being dangerous.

I guess it is best for you to test out these options on the freeway, then, for your own information if not for general info: What happens if you are at speed and turn ignition off/into neutral? Have you tried, to see if it works, yet?

[CaptainBeowulf]

that Maestro was the second direct injection diesel engined car ever to be sold (the first was a car called the Fiat Tempra) and it did it with a mechanical pump and normal aspiration

Chris, that's really interesting to know. If we can do that sort of thing without needing computers, we should. I think it would be a fantastic challenge to get together a team of engineers to build a high-efficiency car which would still have decent acceleration/top speed without any computers needed.

I love computers, I just don't think they should ever be used unnecessarily. Even in the robotic mind in a tin-can spaceship scenario, I would like everything to be mechanical except for the computer my mind actually runs in - that one computer brain would be able to control everything mechanically, not route commands through submodules which are other computers doing fly-by-wire.

Tom, how about this for a short story scenario: Skynet becomes active at 2:14 a.m. eastern time, August 29 this summer. Rather than nuking the world, it simply takes control of all our computerized cars and kills us off by crashing us into each other...

[Maui]

I actually was in a low speed accident this summer that I believe was at least partially to blame on a brake problem (I posted about it here)
My opinion is that there is a software issue, and the electronics are taking away direct control to the point of being dangerous.

I guess it is best for you to test out these options on the freeway, then, for your own information if not for general info: What happens if you are at speed and turn ignition off/into neutral? Have you tried, to see if it works, yet?

I'll let other people try it... and they have. Here is one thread about it for example.
It seems neutral is definitely preferred over turning the car off, because if you turn it off (requires the button to be held for 3 sec), you lose power steering, etc.

[MSimon]

What makes fly by wire work for aircraft is extensive testing and certification. Failure modes are documented and if you have a module where single point failure would imperil life you get triple redundancy. And regular checks of operational quality.

You couldn't afford to drive such a car.

[hanelyp]

On the radio today a 911 tape from an incident of Prius "sticking gas pedal failure" was played. The 911 operator suggested putting the car in neutral to disengage the engine, then later shutting down the engine when the driver failed to respond coherently. Sounded to me like the drivers brain was in neutral. Or a 'software failure' between the ears.

[AcesHigh]

if it were manual shift, there would be no such problems! Just pressing the clutch would magically solve the problem.

[Tom Ligon]

Chris,

I tried an experiment on a wide road with no traffic near here, speed around 25-30 mph (definitely not full throttle) in a 2002 Ford Focus with automatic transmission.

Turning off the ignition switch while moving does not cause steering to become difficult, and the brakes still functioned adequately (conventional hydraulic brakes with power boost and ABS). I left it in Drive to see if it would slow the car ... it does some. This particular car will not allow the key to be turned to the lock position unless the transmission is in Park, an experiment I don't intend to do while moving in my wife's car.

The car restarted easily when I turned ignition back on.

The Prius has a peculiar transmission that couples the gas engine to the electric system (there is a Wikipedia article on it, which is being updated with every new malfunction). It is very likely computer-controlled. I'm not clear that it functions like a conventional transmission such as most of us are used to.

[chrismb]

That's how it is for most cars in my experience. I work with designing and testing electric steering systems, and they are designed to generate as little torque drag as possible, so de-powering an eps should mean a smaller loss of assist than in an equivalent hydraulic system

So I don't really understand the issue of the stuck throttle. If I am coming up to a junction where I know the lights are on red for a long while, then I'll probably turn the engine off way back and just coast up to the lights. Not so frequent in UK 'cos most of the people that programme the timing of traffic lights don't seem to understand much about traffic flows! I recall in Kuwait I thought well of their traffic light system - for lights coming off the freeways they'd put a 'red' up for, literally, a few minutes at a time. But the flip-side is that you then get a green for a few minutes at a time. It really helps with traffic flows doing that at peak hours because you're not wasting all that 'inter-green' road-space time when everyone has red lights. Mind you, you don't want to be turning off the a/c there any time between Febuary and November, but if it wasn't too hot you could turn the engine off a good half-mile back, looking ahead if the light had just gone red.

[chrismb]

In the days of fully hydraulic gearboxes, you used to be able to jump-start an engine by putting it into gear at speed (just like with a manual car), but these days with all electronics I'd not want to try it. I used to have a 318ci Plymouth (here in UK) and I found the handbook quite hilarous because in it it offered a way to start cars where the battery had gone flat: Basically, you drive up behind the car with the flat battery and then push it, bumper-to-bumper, with the pushed car in 'D'. The picture showed, helpfully, the insertion of an old tyre between the bumpers of the cars, so as to minimise any damage risk to the bumpers.

I dunno how fast the book was expecting anyone who tried that to get up to, but you gotta go fairly quickly to get an auto to do that!

These were the days of the US test which said cars had to survive a bump into a brick wall at 5mph and show no sign of damage, hence the huge bumpers of early 70's cars, such as mine was.

[chrismb]

that Maestro was the second direct injection diesel engined car ever to be sold (the first was a car called the Fiat Tempra) and it did it with a mechanical pump and normal aspiration

Chris, that's really interesting to know. If we can do that sort of thing without needing computers, we should.

I wouldn't get too excited - the issue is emissions. For diesels, particulates and NOx are big issues and all the electronic gubbins was originally put in for the fine control of fuel so as to minimise undesirable emissions, rather than for power or other such.

These early direct injection diesels kinda got to market quicker than the regulators could regulate against them. The Maestro diesel ( a Perkins deisgn, I believe) was a touch on the 'smokey' side under start up and high load conditions.

As an engine designer recently said to me; these days anyone can slap an engine together from supplier parts, but the trick is getting it through homologation [as the emissions regs are so tight].