Talk:Sudden unintended acceleration

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High traffic

On 3 March 2010, Sudden unintended acceleration was linked from Slashdot, a high-traffic website. (See visitor traffic)

Opposing the use of "Sudden"[edit]

It is my understanding that the current (2/'10) concern regarding this matter involves the rare failure of certain powertrains to return to idle setting upon release of the accelerator pedal. To introduce the word sudden is to imply that there is danger that a vehicle is prone to accelerate wildly regardless of driver action. There is no evidence of this, at all.

Unintended acceleration is strong enough language. Homebuilding (talk) 13:26, 11 February 2010 (UTC)

From what I've seen of the sources, there is no real consensus regarding that. Were that the case, I would agree, and I actually was prepared to make that comment here myself, but sources pretty clearly use the word "sudden" on a lot of occasions and my impression is that the Wiki is meant to reflect the work of others rather than strike out on its own.
Whether or not "sudden unintended acceleration" winds up being the way this phenomenon is remembered will depend on what facts eventually come out. However, as long as there is a good possibility (and there is) that this is an electronic control problem rather than a problem with the physical arrangement of the pedals, that language needs to stay.
J.M. Archer (talk) 14:53, 11 February 2010 (UTC)

This is an encyclopedia, not ABC or Fox "...over-emphasize so we'll own the story" news. All sources so far indicate unexpected failure of the engine to return to idle setting upon driver expectations and/or inputs. Sudden is an unnecessary modifier and in ten years, all of this will fall under something more inclusive, such as "Automobile System Failures Relating to Electronic Control Systems." After all, 2012 will bring more mandated systems for Vehicle Stabilization Control--where the machine will be designed to specifically over-ride destabilizing driver inputs, as interpreted by the software "brain." This is likely to be a fiasco as the machine will not be able to correct fully for all driver errors. Will the companies be liable if a surviving passenger testifies that "...the driver couldn't make it steer back on the road" when the brain was attempting to prevent a roll-over (one of the main functions of these systems)? Homebuilding (talk) 00:22, 12 February 2010 (UTC)

References to "sudden acceleration" are promoted by plaintiff's attorney groups whose information cites "thousands of deaths" and when the "....engine suddenly goes to full throttle." All inquiry, to date, show these statements to be wildly over-estimated, gross falsehoods which are made, most likely to promote panic and provide for plaintiff attorney employment. I will defer and appeal to a higher level.Homebuilding (talk) 00:45, 12 February 2010 (UTC)

Whatever the sources say regarding the cause or circumstances, the sources use the "sudden" terminology, and that's the point that matters here--regardless of their reasons for doing it (particularly as it isn't our place to decide whether or not they're right). Additionally, I would argue that "sudden" serves a useful purpose in any case because there is a second class of unintended acceleration that (reportedly) happens gradually as the cruise control (or the driver's foot?) advances the throttle bit by bit. Is it possible that the word 'sudden' is intended to differentiate?
J.M. Archer (talk) 16:20, 12 February 2010 (UTC)

The BusinessWeek March 1, 2010 issue pp. 14 - 16, titled: "Did Toyota's Traffic Cops Sway the Regulators?" discusses "....the Japanese automaker fended off four U.S. probes of auto defects dating back to 2004 with the help of two former NHTSA regulators on its payroll." The box at the end of the article states that Toyota received 478 incidents of complaint regarding Tacoma pickup truck engines (2004 - 2008) alleging that engines speeded up even when the accelerator pedal wasn't pushed.

Throughout the article, the problem is referred to as unintended acceleration or accelerator problems. The word "sudden" does not appear.Homebuilding (talk) 01:00, 21 February 2010 (UTC)

Maybe I ought to clarify my position, particularly as I don't use "sudden" myself in the context of the article: I think the title should include the word words, and that we should introduce the topic as such, so that readers understand this is the article they're looking for when they come looking for information on 'sudden' acceleration. I've got no interest in typing "sudden" every time I refer to the phenomena, and "unintended acceleration" is probably quite sufficient once we've established the topic.
Different periodicals will have different treatments of the subject matter. I'm not certain any of them is definitive, or that we shouldn't also be pointing out that "sudden" acceleration is just one type of unintended acceleration problem and that there are others, or that periodicals not specifically referring to "sudden" acceleration aren't doing themselves a disservice in light of evidence that there are also incidents of "gradual" acceleration... But anyway, yeah. :)
A question: do you believe we should change the terminology for all such incidents, or only for the recent crop of incidents involving Toyota cars?
J.M. Archer (talk) 15:44, 22 February 2010 (UTC)

Maybe we should solve this by having an entry for Sudden and Inaccurate Press Reports of Difficulties Experienced During Automobile Operation. In the course of months since the accelerating Toyota panic, other problems have come to a more intense light, namely SUV rollover. Were any of these "sudden?" I'll bet so, and nearly every crash is sudden, as well.

Remaining Truly Yours for the lack of repetive redundancy.

homebuilding (talk) 16:45, 08 February 2011 (UTC)

Brake failure OR tag[edit]

I got rid of the tag because this is definitely not the first time I've heard it mentioned that brakes don't work during an unintended acceleration event. (I want to say "uncommanded" because that sounds so much cooler and they use it when talking about airplanes, but oh well.)

As it was explained to me, brakes are powered by engine vacuum (rather than by an electric motor or some crap) and the vacuum is occupied with sucking in fuel when throttle is maxed out, so they don't actually have full power (or cannot recuperate power) while the engine is racing. I have no source on this, but most of the news articles I've read have mentioned that braking power is shot during such an event, so perhaps the next person industrious enough to add the tag could instead add a reference.


Actually, I would note that (if the description I heard was accurate) it isn't a brake failure, per se; the brakes are working as designed--it's just that they aren't designed to work in those conditions. I'd have to have a peek at the linked page there to say how appropriate the link and phrasing is.

J.M. Archer (talk) 15:55, 2 February 2010 (UTC)

Oh. There is no linked page. It's one of those red ones. Maybe when I remember to think about it I can look up a source and add a more accurate description. J.M. Archer (talk) 15:58, 2 February 2010 (UTC)
Update: I did find a source for the brake failure thing. Looks like a consumer reports article, but the URL I have for it actually points to... Well, here:
So, yeah. The engine vacuum thing. I don't feel "bold," but there it is. =) J.M. Archer (talk) 20:40, 2 February 2010 (UTC)

Apparent Egregious Error (Toyota) in Operational Design[edit]

""""""Elevated power settings (planned or unplanned) in a gasoline engine makes less suction available to vacuum-boosted power brakes. Application of the brakes at such a time may be perceived as reduced braking capacity, though in general, more forceful application of the brakes will stop the vehicle. Most cars with electronically controlled throttle function, automatically default to the idle power setting when the brakes are applied, thus instantly creating the level of vacuum needed for normal power brake usage."""""""

I have added the above to the article. The current Toyota recall does not address the absolute need for the "fuel setting to idle upon brake application" defeat switch can be easily wired into the brake light switch circuit. Other manufacturers do have this defeat function and Toyota can be expected to provide this fix, quickly, or it will be mandated by various national government agencies. —Preceding unsigned comment added by Homebuilding (talkcontribs) 16:51, 6 February 2010 (UTC)

I'd like to see something about how a switch of that sort would affect a car with a manual transmission. And sure, that kind of information is pretty trivial in comparison to the overall topic, encyclopedias are good for this kind of thing. My worry is that anything anyone might have to say on this at this juncture would constitute original research, but if anyone has a source I'd like to see something on that added to the article. J.M. Archer (talk) 19:13, 8 February 2010 (UTC)
Interesting concern, Archer. My reading, back during the highest levels of concern pertaining to unexpected AUDI acceleration times--none of the reports of sudden acceleration (from Audi or any other manufacturers--as the press concentrates on only one car builder at a time--complaints regarding nearly all other manufactures are reported to NTSB at continuing and regular intervals) involved manual transmission vehicles. I believe that is the case now, as well. Further, there are no reports that Toyota engines (or engines of any other car manufacturer) revved unexpectedly, without driver command to very high rpm in manual transmission-equipped vehicles. Many things point to driver error, here. User:Homebuilding (talk) 19:13, 16 February 2011 (UTC)

Edit/expansion of Feb 12[edit]

I noticed that some of the bullet points on the lists ended in periods and others did not. This annoyed me. I set out to fix it. What a dumb idea.

I wound up making new bullet points and incorporating other information from bullet points into new paragraphs which I ordered from Sears. Luckily, Fed Ex has same-day delivery for that kind of thing.

I suck at teh citazshuns, so I didn't add any to the new paragraphs. I'd appreciate some help with that, but will try to come back and add more later on if no one beats me to it.

"Incursion" was all wikilinked, but it actually points to a video game of the same name. The only dismabig article was about runway incursion as relating to airports and such. As far as I can tell, there is no article for "incursion" as used in this instance. The term is pretty simple and this particular use probably doesn't warrant a wikipedia article all its own (perhaps a section in this article, at most?), so I was wondering if it was possible to link something like that to wiktionary instead.

J.M. Archer (talk) 17:14, 12 February 2010 (UTC)

Oh, for Homebuilder: at least for the section I just updated, I did use "unintended acceleration." Wasn't interested in typing three words over and over again where two makes just as much sense, and even if "sudden" is a valid subset of all types of "unintended acceleration," I would say most of the junk I just added is applicable to all types.
I figure "sudden" is more important up top, so that people coming into the article understand that they've found the right place and that the article does cover the stuff that's been in the news lately, but my fingers are lazy and, besides, you only say "National Aeronautics and Spinach Club" for the first occurrence, and then you can get away with "NASC."
J.M. Archer (talk) 17:18, 12 February 2010 (UTC)
Another note: my tone might be off in the material I added. The heading for the section is "Possible causes" and I may have used language that implies too much certainty. Open to comments or modifications.
J.M. Archer (talk) 17:21, 12 February 2010 (UTC)

Hi, 842U! Thanks for your help. Read through one of the sources already cited in the article to find a citation for the bit about brakes not working in an "SAI" event (that's what they call it in the PDF, I swear. >.>). (Actually, that may be a handy note for Homebuilder: apparently, the "sudden" appellation goes back some time, to when it would be a "sudden" event on shifting into drive or reverse; there's a good possibility that it was more applicable back then, in which case the main reason we're still hearing it is that this sort of occurrence is simply already labeled as such in public consciousness.)

842U: you did make one edit that I wonder about and I thought I'd bring it up here in case you're watching and have some insight that I don't: in making this sentence

An unresponsive accelerator pedal may result from incursion; i.e. blockage by a foreign object, or any other mechanical interference with the pedal's operation — and may involve the accelerator or brake pedal.

shorter, it seems as if you may have also introduced a little ambiguity, or something. The sentence starts by saying that an unresponsive accelerator may result from ... and ends saying that the incursion that caused it may involve either the accelerator or the brake. It seems unlikely to me that a floor mat or a drink cup or a small dog interfering with the brake would make the accelerator unresponsive, so I'm pretty sure that's not what you mean by that. Perhaps the sentence needs to be a little longer to give proper context to those statements?

J.M. Archer (talk) 21:45, 12 February 2010 (UTC)

I dumped the original research tag thing and added it back as I thought initially it referred to the one thing 842U tagged as [citation needed] but then felt uncertain. As I'm quite new to the whole sourcing thing (I usually stick to moving commas, per my stated M.O.), I'd appreciate any tips as to what else needs to be cited (or excised) to quell any worries about original research.
Additionally, I got to thinking that two of the 'acceleration factors' mentioned might be kind of redundant. Is there any reason those were listed separately?
J.M. Archer (talk) 21:51, 12 February 2010 (UTC)
The "sudden" terminology does go way back, possibly starting with the Audi concerns and resulting lab tests. You are right, it does seem to be the established term, however I'll continue to suggest that it's unnecessarily inflammatory, as we all know that a mechanical failure is a mechanical failure--and even if its' unexpected or difficult to manage (and seems to develop suddenly). Whenever possible, I'd like to see a category of problems discussed with a general title that allows more specificity underneath. For example here we have room for a) mechanical failure of fuel settings to return to idle b) electronic failure to return to idle c) vacuum boost loss from unexpected, yet sustained throttle open settings d) vacuum reservoir failure or leak (low readings) causing (non-driver directed) increased power settings, etc. As I've said before--since this topic is so closely related to problems with electronic vehicle system management, it will probably need to be subsumed into a larger heading soon. (talk) 04:14, 14 February 2010 (UTC)Homebuilding

Not sure you're right about "sudden unintended acceleration" referring to a specifically mechanical problem, or somehow excluding an electronic problem.

J.M. Archer (talk) 15:47, 22 February 2010 (UTC)

OR tag?[edit]

I'm not "new" to wikipedia, but I'm too lazy to have learned much about this process, and also too lazy to deal with any trouble I might get myself into by striking out on my own...

The OR tag. What parts might be original research? What do we need to cite to get rid of it?

J.M. Archer (talk) 15:48, 22 February 2010 (UTC)

Copy/pasting crap from my talk page here, as it seems like it doesn't belong in private (J.M. Archer (talk) 20:04, 25 February 2010 (UTC)):

Find citations for important information that has none. In this case, when there is a list of so-called causes of sudden unintended acceleration, several of which have no backup... that might be a clue.

When editing contains information that's important, but unreferenced, it is then by default the editor's own conjecture, hence "original research." Original research isn't allowed; the reader has no way to verify the information, and verifiability is key. By placing the tag over the section, you're telling the reader to be on guard. Substantiate the info and the tag can go. Hope this helps.842U (talk) 19:04, 25 February 2010 (UTC)

The only one without a supporting source is "pedal misapplication." The others are sourced, but inline references are either in the wrong place or missing. When I say "missing," I'm referring to the last one--"other on-board computer or electronics failures," which is simply another way of stating the next to last cause, and which could share its source. I was gonna delete that one, but didn't want to insult whoever added it in the first place. >.>
I can address two out of three in about a minute, but do you really believe we need a source for the claim that pressing the gas pedal inadvertently can cause a vehicle to accelerate unexpectedly? That point seems neither obscure nor important.
With those out of the way, I'll ditch the tag and if anyone has any other issues they can re-add it.
J.M. Archer (talk) 19:15, 25 February 2010 (UTC)
Actually, the article on stuck throttles addresses pedal misapplication. J.M. Archer (talk) 19:17, 25 February 2010 (UTC)
Though, the references may not meet wp:RS, and oddly, you are reposting it after I just it's being included as an overly promotional external link? 842U (talk) 19:58, 25 February 2010 (UTC)
I didn't repost anything. Those links were all already there. Also, the rest of what you just said did not make a lot of sense. J.M. Archer (talk) 20:02, 25 February 2010 (UTC)

Ohhhh, I see what's going on...[edit]

I add inline citations for the disputed items and then someone else deletes the references as "promotional" so they can claim that the items are still unreferenced.J.M. Archer (talk) 20:06, 25 February 2010 (UTC)

There must be a zillion links that would support pedal-misapplication. The source you cited would not come close to being considered a reliable source. Sorry. I didn't make the rules. 842U (talk) 20:23, 25 February 2010 (UTC)
Find one of the zillion next time instead of aiming veiled accusations in my direction. J.M. Archer (talk) 20:31, 25 February 2010 (UTC)
There is no accusation, veiled or otherwise. You used a source right after I had removed it from the article as non-rs. You're entitled to your own conclusions, but I did not accuse you of anything.842U (talk) 20:44, 25 February 2010 (UTC)


Pedal misapplication link:

Report by National Transporation Safety Board.

Stuck pedal link:

I know it's ridiculously long, but what are ya gonna do?

It occurs to me that we don't address the possibility, raised in many of the sources, that the throttle could stick independently of the pedal itself, so...

Possible link for "stuck throttle" without the whole "pedal entrapment" thing going on:

For 842U: I can see now what you must have thought was going on, but I didn't add the link to the mechanic's website in the first place; I copy/pasted it from the paragraph you removed it from to the end of the two lines it contains references for. While I disagree that it seemed "overly promotional," I do think it would be best to avoid any controversy regarding sources, and so I've provided these in an attempt to sidestep any issues. If I can figure out how to actually add a reference, I'll slip these into the appropriate spots.

J.M. Archer (talk) 20:30, 25 February 2010 (UTC)

NHTSA for stuck throttle:

CNN for stuck throttle (weaker):

J.M. Archer (talk) 20:38, 25 February 2010 (UTC)

Ok, everything is added and looks to be working. Not that I would know.

J.M. Archer (talk) 20:40, 25 February 2010 (UTC)

What are your thoughts on the still unsourced latter portion of that section? 842U (talk) 20:49, 25 February 2010 (UTC)
I was just going to ask you about that. (Unrelated: I think I may have worn out my wireless keyboard's battery like two years early. Is this common for writers, I wonder? >.<) I'm not a fan of how the article is organized--both the engine control system and the braking system are factors in such an incident, but braking system factors are not causative, and I'm afraid that lumping them in with engine control factors may be muddying that.
As no one in their right mind is blaming the braking system for causing engine control problems (no source I've seen, anyway), I don't see those items as being quite so controversial, and there is no need to get sources directly addressing acceleration problems to substantiate problems with brake boost and brake fade.
The bit on the brake interlock switch could use a source, and I think it would be best if the source for that specifically addressed the usefulness of an interlock in the context of a sudden acceleration event, as I can imagine such a thing would be pretty useless on some older model cars--and yet I don't think any of the news articles I've seen have addressed that, so maybe I'm wrong. Still, I'd like to see that addressed in the paragraph on the interlock (which I think I added, so I have only myself to blame).
It occurs to me that you may be referring to the material in the middle, which is intended to elaborate on the causes given in the bullet points above. Much of this material should be supported by the sources I added a few minutes ago, but the paragraph that talks about "other causes" probably won't be; that was a bullet point that I deleted because I thought the list was too long. I believe that material was taken from the source that you deleted earlier. I don't think we can find just one source to substantiate that paragraph as I doubt there are many articles that address such a wide variety of issues. I know that the chafed cable thing comes up in one of the NHTSA reports I linked to, but I've no idea where we'd look for the rest. I guess start Googling "unintended acceleration carburetor" or something. On the other hand, I don't know if it seems particularly controversial that worn springs could cause problems with something not springing back into its resting position.
It might be worth our time to take a look at the wikilink for driver error and see what sources they used for pedal misapplication; I notice that the removal of that other link lost us some documentation for that as well.
J.M. Archer (talk) 21:08, 25 February 2010 (UTC)
Everything I can find on an interlock refers to the fact that you have to hit the brake to shift out of park. -.- Of course, I can't view half the intarweb from here... J.M. Archer (talk) 21:23, 25 February 2010 (UTC)
Somewhere I saw a report that left foot brakers are more likely to hit a pedal and assume it's the brake because it's their left foot. Right foot brakers apparently have a better feel for distinguishing the two pedals. However I have no reference. (talk) 18:35, 5 March 2010 (UTC)


Has anyone seen this term bandied about at all? Generally it describes an equipment malfunction rather than operator error and, as the nature of these incidents is often in doubt, I am not surprised that I don't see it more often--but I'm curious as to whether or not it has been applied, or should be applied here to describe specific categories of incidents, perhaps in keeping with a desire expressed by some to be more precise.

J.M. Archer (talk) 16:35, 2 March 2010 (UTC)

Restructuring of March 2, 2010[edit]

Addressed some concerns I noted last week regarding the braking section. Added a few sources for the brakes stuff. Found that we have a wikipedia article about manifold vacuum and how that affects brakes, but it appears to have been written by an expert on the subject (who I am sure was correct about everything and who knows all of this off the top of his or her head) and, unfortunately, does not include any sources I could steal.

However, none of that information seems to be particularly controversial except to the sort of person who pays a mechanic to "refill headlight fluid." So I left it for now.

I added FACT tags to the bit about "brake-accelerator interlock switches" and the other thing, which I'm sure constitutes original research until we can find someone more expert than me to present the same concern, but I hope that my fellow editors will help in finding some kind of source for those two bits rather than just striking them. (And note that I didn't make up the first one; someone else added that. >.> )

J.M. Archer (talk) 17:00, 2 March 2010 (UTC)

Rearranged the interlock part so that there is no need to point out that something like that wouldn't work in the even of one of the possible mechanical failures mentioned above and removed the attendant uncited sentence. Also found a cite for a 'brake-accelerator interlock switch,' though Consumer Reports calls it a 'smart throttle' instead. Fact tag removed. J.M. Archer (talk) 17:08, 2 March 2010 (UTC)

Sources again[edit]

Ok, I worked to find what I could for the unsourced stuff in the section on braking and I think it's an improvement. Any improvement to my amateur REF tags would be appreciated; I'm still working on getting them to display correctly.

Appreciate any help on fixing any other issues anyone might spot, and would also appreciate a source for manifold vacuum/brake boost, etc., cuz even though it doesn't seem controversial, I figure an article on something that is basically controversial should be ironclad on whatever known facts there are.

J.M. Archer (talk) 17:11, 2 March 2010 (UTC)

Section for Jeep data?[edit]

The Audi thing has its own section at the bottom, providing kind of a cautionary example of how fallible we all are. Perhaps the Jeep thing should go in a similar section, perhaps just above it, as sort of a balance?

J.M. Archer (talk) 19:00, 2 March 2010 (UTC)

If you're going to delete sources...[edit]

Feel free to look up new, better ones yourself. J.M. Archer (talk) 14:11, 16 March 2010 (UTC)

(I'm grouchy because I can't find any articles that state the obvious with regard to the difference between old school "shift into drive" sudden acceleration and newfangled "cruising down the highway" sudden acceleration and someone just deleted the mediocre source I found for that. Hopefully no one will be legalistic about that stuff, as I doubt it's particularly controversial, but who knows? ...and I'd rather have sources one way or another anyway.) J.M. Archer (talk) 14:28, 16 March 2010 (UTC)

So I read the RS page at Wikipedia and am now pretty sure that doesn't pass muster. I've removed the remaining links to it (I think); hard to know, as I didn't add most of them. The one thing that still concerns me is that I don't think we have any citation for the difference, asserted in this article, between acceleration events seen in '89 (shifting from park) and those seen in recent times (while cruising). Any help would be hot, cuz I'm striking out on this one. :) J.M. Archer (talk) 14:37, 19 March 2010 (UTC)

Removal of 'Effects on Braking' section[edit]

I am going to remove the 'Effects on Braking' section because it is unsourced for all but two references. I read through both of these references and they do not substantiate any of the claims made in this section, except for the two exact sentences they are linked to, and even then there appears to be synthesis. I'll be happy to discuss further with anyone that disagrees, or you can just restore it, but I really do believe this section is extremely lacking in sources, to the point of adding bias to a fairly politicized issue. --Aka042 (talk) 01:07, 9 February 2011 (UTC)

All Toyota Prius 2010- obviously has this potential problem in the SW[edit]

All Toyota Prius is indeed full of electronics controlled by software programs.

The Prius 2010- has an electronic parking button and an electronic gear selector. The SW is connected to the brake pedal sensor to allow the car to enter parking state or drive state. If the SW is not detecting the brake pedal is pressed, there is an alarm of two beeps. But there are alarms for everything in that car and in most cases the driver is focused on something else, the reason for the gear shift. The problem is that except the alarm beep, the SW in gear shift failure, is then moving the gear to neutral, or sometimes doing nothing, leave the car in drive state. It means that the driver can leave the car without the parking state is in effect, the car can runaway without a driver, the typical “Sudden unintended acceleration” syndrome.

In regular automatic gearboxes the physical gear selector is blocked from entering the parking state without the brake pedal detection. The physical gear shift can’t be moved, which makes the driver aware the parking state is not in effect. But here there is just a button and the button is not physically blocked, possible to press and the driver assumes the car is in parking state.

It is also hard to make the Toyota service organisation accept that there is a problem with the brake pedal pressure sensor, and get it adjusted right. And if adjusted right it soon malfunctions again. Other cars of the same model, have OK brake pedal pressure sensors, and they stays OK. Why?

So normally the brake pedal sensor is correctly adjusted and the syndrome is rarely obvious. But if the brake pedal sensor is not adjusted correctly and fail to indicate the brake pedal is pressed, this syndrome will be a common experience for the driver both in pressing parking button and drive state gear selection. The car then refuse parking and can and will just run away of itself, or refuse the drive state one or several time after each other, beep beep beep beep. The real issue is that it can run away of itself, that the “Sudden unintended acceleration“ syndrome is possible.

The correction should obviously be in the SW. Obviously the electronics should, if the car is halted or almost halted, if there is a need of protecting the gearbox, if brake pedal pressure is not detected and parking button is pressed, first select the electronic parking brake state instead. Doing nothing is not enough and neutral state must be seen as a top security issue of human programmers logical error. But in fact nothing is more dangerous because the engine will run the car, it will not just roll away down a slope.

But Toyota service states, that it can’t select parking while moving to protect the gearbox, so the SW is correct. The service organisation does not want to initiate the fix and are obviously not ordered to report to the central SW or product departments of such problems. Most likely the authorities making type approving is not used to such electronic devices as a Prius, and fails to detect the issue. (One can really wonder why there aren't more electronics in new cars, for instance standard GPS and electronically adjusted speedometer, a series of standardised speed (limit) fixed cruise control buttons and a standardised user PC/Mobile phone car information interface.)

In the perspective of the Audi 5000 scandal it is amazing that the Toyota Prius “Sudden unintended acceleration“ case, is not in the open debate yet. Especially in the perspective of the huge impact in the market of the Audi 5000 scandal. But there are no obvious instances to report this kind of syndrome (I reported it to the road security authorities and insurance companies and no reaction) and most likely there is a need for a TV show like 60 minutes to put a topic like this on the agenda. There are a huge number of Prius out there, far more than the Audi 5000 and most likely the manufacturer get away with it. Toyota service demanding that the accident (insurance) report should be amended because they do not recognise the damage syndrome possibility, claim the car is all OK, can't be (and if, they would have to pay the repairs most certainly).

The car is real great in all other aspects, but this is a true horror and frustrating. — Preceding unsigned comment added by (talk) 20:31, 27 March 2012 (UTC)

All this is about what the Prius should do. Wikipedia is only about what it does do. This talk page is about how to improve the article, not about how to improve the car.  Stepho  talk  22:17, 27 March 2012 (UTC)
It is a talk about what it do (the syndrome itself), anyone can replicate the behaviour of the syndrome on any Prius 2010- even with OK brake pedal sensors, it is obvious the SW is allowing it. And that the syndrome is active and puts the question why and how it is put on the agenda, does it need 60 minutes? — Preceding unsigned comment added by (talk) 09:14, 28 March 2012 (UTC)
Read up on WP:Original research first.  Stepho  talk  22:51, 28 March 2012 (UTC)
This is not the article, it is the talk. You must have misunderstood the Original research issue. If something is replicable by anyone, it has a huge higher scientifically value than any kind of hearsay, like reports. Physically replicable appearances are indeed so strong that they scientifically wreck any report. In this case it doesn’t matter because this is talk, and not the article. What is interesting in this topic of the talk is if the subject of the article is a physical topic or a media topic? I think it is a very important issue about topics like this. — Preceding unsigned comment added by (talk) 05:43, 9 April 2012 (UTC)
WP policies require a reference. The policies even state that verification from reliable, published, references is more important than truth. If it isn't published somewhere then it doesn't exist as far as WP is concerned. If you can find a published reference (eg magazine but not wikis, blogs and forums) then I'd have no problem with it going in the article. The talk page is only for talking about improving the article, so it doesn't really belong here either but I'm not going to take any action to remove it.  Stepho  talk  08:21, 9 April 2012 (UTC)
We have a multiple topic situation here. what a scientific reference is, what the purpose of the talk is and what Sudden Unintended Acceleration (SUA) is (a technical or a media topic). My intension is to ask the last question, on the basis that there are no doubts there are at least one by any party having a Prius at hand to be able to replicate the technical discription of Sudden Unintended Acceleration (SUA). So the article is about a media issue rather than a technical issue and the matter is rather a question of being published prefereably in 60 minutes. I think the media aspect of this issue should be lifted forward in this WP article but I don't like to intervene in the article text myself. I rather want a debate on the issue that ends up in a standpoint of this aspect. The request of pubished references of my opponent is a cicle argument when the topic of this talk section is the question if this is a matter of being published or a technical syndrome. I hope for some debate on this, if we do not get it it means this article is very single in its perspectives and could be commented from a scientific point of view. Let's hope for some response on the topic. Remeber this is a talk, and not the article. (I admire people with such faith in published words rather than replicable true science tests. Me myself wonders if the weather will be bad when the newspaper writes sun on the tabloid. We have a scientific world of a large number of articles being scraped after there has been a replicable test proving the articles are wrong. It would be the day if WP is not sensitive for replicable science tests? Wonder if all believes in the written gossip in Facebook?, see Experiment) — Preceding unsigned comment added by (talk) 00:48, 3 May 2012 (UTC)

──────────────────────────────────────────────────────────────────────────────────────────────────── I see where you are coming from and agree with you for much of it - I try to read published articles with a bit of skeptism rather than blind faith. Unfortunately the rules of Wikipedia want verifiable published (and peer reviewed) sources and are very much against original research - as specified in WP:VERIFY and WP:OR. This means that scientifically reproducible results done on an actual vehicle are great for writing up an article in a science journal but are not allowed on Wikipedia. For the record, Wikipedia considers Facebook to be a very unreliable source. Does that make us biased? - only to the extant that the publish media is biased. But at least we get to present the viewpoints of multiple sources. So if most sources say the sky is blue but a few say the sky is green then we can say 'the majority (such as Fred X) say the sky is blue while a minority (such as Joe Blogs) say the sky is green'. The key point is to find a published, reliable source that supports what you are saying. Then we can happily include it.  Stepho  talk  06:49, 4 May 2012 (UTC)


Many people don't seem to be aware of the fact that the brakes are stronger than the engine. Even if the throttle gets stuck open a car running at full engine power would still be able to stop unless the brakes fail as well. Without any explanation why this would happen I suggest being more skeptical towards reports of cars getting out of control. (talk) 11:01, 6 October 2015 (UTC)

Nope. Brakes are more powerful than the engine at idle and even when the engine is at about half power but at full throttle the engine can overpower the brakes. Especially when the car is already moving. Brake fade also comes into effect, where the brakes overheat after repeated application and lose their effectiveness.  Stepho  talk  01:54, 7 October 2015 (UTC)
What you say makes no sense. I suggest you provide some proof to your claim or some kind of argument instead of just claiming you're right. (talk) 23:16, 7 July 2016 (UTC)
Which part are you confused about? Brakes apply a constant deceleration force (until brake fade kicks in after repeated attempts to stop) which can be calculated from 100 km/h to 0 times and the mass of the car. Whereas engines have a range of acceleration force varying from least at idle to most at wide open throttle. Brakes are normally spec'd to keep an automatic gearbox car stopped when idling, to stop a car when the engine is not at wide open throttle. Brakes are assumed to be not wanted at wide open throttle, so they do not have to be strong enough to stop a car in that situation. Naturally, the constant brake deceleration force falls within the range of engine acceleration force. If you want further clarification then you have to ask a more specific question.  Stepho  talk  23:40, 7 July 2016 (UTC)
This claim makes no sense. The principal deciding factor in braking distance is the adhesion between the road and your tires, not the strength of your brakes. Virtually all modern cars can provide more braking force than their tires can handle, hence the development of anti-lock brakes. Non-sporting cars, especially eco-friendly cars with low rolling resistance tires, will be even more limited by their tires' adhesion to the road, rather than the force produced by their brakes. The stopping distance from 100 kph *will not* be indicative of the peak braking force.
But let's assume that it is anyway. A typical stopping distance might be on the order of 125 feet (e.g. Nissan Altima; 128, Subaru WRX, 125, Hyundai Genesis, 125). For 60-0 mph, that takes about 2.86 seconds (assuming the deceleration is linear, so the average speed is 30 mph). That means that the car produces a deceleration of ~-0.95 g. For a 3400 pound car, this puts the braking horsepower on the order of 500 (braking HP = 0.002667 * mass (pounds) * speed (mph) * G-force), and does not include the fact that under such conditions, the anti-lock braking system will be activating (i.e. the tires are limiting deceleration g's, not the brakes). This means that the full braking HP will be higher, since the car could stop faster if it had better adhesion - I've heard that a braking horsepower on the order of 1000 or higher is not unheard of for road-going sports cars, particularly if we consider only the front brakes (keep in mind: to stall your engine, only the driven wheels need to be locked up).
So no, it's not unreasonable that most cars, especially production economy and mid-range sedans, whose engines are *not* tuned to provide maximum torque at very high RPM and produce *far* less than 500 bhp, will have brakes that are *vastly* stronger at *any* point than the engine. The claim that brakes are tuned to keep the car from moving at idle, or even half-WOT, is *blatantly* false. All production cars will ship with brakes *vastly* more powerful than their engines that are designed to bring the car to a full stop in as short a period of time as can be achieved with the tires specced for the car.
(for the curious, the key to stopping a runaway car with the brake is to shift the car into neutral, if you know how, then a) take your foot off whatever pedal it may be on, even if it's already on the "brake", b) make sure your foot is really on the brake, and c) try to fuze the brake pedal to the floor, no mercy, until the car stops) (talk) 04:49, 4 October 2016 (UTC)
Fair point about needing to allow for the braking ability of the tyres. Although to say that the strength of the brakes is irrelevant doesn't make much sense - otherwise a Chiron could have the tiny brakes of a 1970 Corolla. The reality is that the braking force is the weaker of the brakes or tyres at any given moment. Also remember that brakes fade when used over a longer time period - so brakes that can hold back 500 hp once or twice often stop being effective when asked to work for over minute or to to the same job 10 times quickly in a row. This is why we have vented brakes, high temperature brake fluid and why race cars have air ducts feeding into the brakes.
A quick search with Google pointed me to a web page that has 60-0 mph braking distances for typical American vehicles -
I will use this data to do some number crunching on the weekend and get back to you early next week - once I get my head around the weird medieval measurement system.  Stepho  talk  23:25, 5 October 2016 (UTC)
Okay. Keep in mind that all that's needed to stop an "unintended acceleration" event is to disrupt the ability of the engine to send power to the wheels, not bring the car to a full stop (this will occur if the engine stalls). Fade should not (I speculate) occur to the same degree if the brakes are clamped shut and not let up on; I believe the heat produced from one panic stop 100-0 kph would not produce enough heat to reduce braking force to the point that the brakes could not hold back the engine, but I'm not sure about passenger sedan brake pads. Beyond that, only the driven wheels need to be stopped (in this case, an AWD car will be hardest to stop) to stall the engine. I'm not up to speed on most automatic transmission cars, so I don't know if, especially in a modern car, they'll recover from a stall, or be capable of "idling" the engine at WOT whilst in gear. In a manual transmission car, rapidly applying the brakes while the engine is accelerating and the car is in gear *should* be enough to stall the engine, if not snap the driveshaft, shatter the clutch, or something else..
Also, I like that the URL and title to that link are the "breaking" distances for the relevant cars. I used to drive a Mitsubishi Lancer and it took considerably longer to break. (talk) 03:48, 7 October 2016 (UTC)

Check out this podcast for an excellent analysis of this topic, including proof that brakes will win over a racing engine; Pjbflynn (talk) 23:33, 9 August 2016 (UTC)

Repeated ref from September 2015[edit]

This complex edit from September 2015 is poorly referenced, but might have notability. I am not sure what to do about it. TGCP (talk) 20:09, 10 January 2017 (UTC)