Video showing you can't stop a runaway toyota with the brakes

Check March issue of Car and Driver for different results on their tests.

Misleading as always and from a very non-credible source.

I'm no fan of CR as far as cars go, though I bet Toyota is. Or was. But I took for granted what you always hear in the auto groups. Namely, that brakes will always overcome the engine. I'm beginning to doubt that. Never tried it myself - don't want to mess up my engine, trans or brakes. But I saw a report that the Lexus that took that California family to their flaming death had it brakes on fire, and this CR guy apparently could only slow down the Camry, and he knows cars. Once those Camry brakes heated up, they'd be gone. He didn't take it that far. Anyway, looks like the "brakes will always overcome the engine" could be just a myth. Might depend on the brake design of a particular car too. "Modern engineering" and designing to minimum weight might have a built in assumption that the brakes only have to overcome car weight inertia, and not applied power. Could be a case of computer-aided design screwing the pooch with minimum weight, whereas the old timers made the brakes beefier to resist fade and simply used massive weight and friction surface to get the job done. Just speculating. Call it talking out of my ass if you prefer.

--Vic

Huh? You didn't actually watch it did you? What is misleading about put in in neutral and don't pump the brakes and it will stop?

I would think it would depend very much on WHICH Toyota- more specifically the horsepower of the engine. Some of them have some pretty wicked engines, others just a normal engine. If you have 350-400 hp under the hood, I assume you'd have to put out a lot of effort, compared to a 150 Hp model.

Vic Smith wrote in news: snipped-for-privacy@4ax.com:

Toyota is on record as saying that the brakes will stop ANY Toyota at wide throttle openings, even the 400hp Tundra.

Here are two excerpts from Toyota Canada web pages:

"Should a driver experience a sticking accelerator pedal while driving, the vehicle can be controlled with firm and steady application of the brakes. The brakes should not be pumped repeatedly because it could deplete vacuum assist, requiring stronger brake pedal pressure."

and...

"If you are unable to confirm the state of the floor mat, or unable to dislodge the floor mat, then firmly and steadily step on the brake pedal with both feet. Do NOT pump the brake pedal repeatedly this will increase the effort required to slow the vehicle."

And that's the problem. Pumping the brakes, or repeatedly letting off on them to see if the car's still accelerating, will overheat ANY road car's brakes. The cop that died apparently did exactly that.

Au contraire. Old-time brakes (I'm thinking especially of drums here) faded with horrible readiness. A moderate hill could be enough to dramatically reduce braking effectiveness and require ever harder pushes on the pedal. Very VERY scary, especially if there was an intersection at the bottom of that hill. This sort of thing does NOT happen with modern discs.

I also remember Consumer Reports car reviews from the '60s and '70s where brake fade was a problem even with the disc brakes of the time. Some cars were worse than others, which made a difference in CR's ratings.

This goes back to my "misleading" comment:

First off, the accelerator will probably not stick in WOT, since most people rarely press the accelerator past 50-60%.

Second, there is no instrumentation used in that demonstration so there is no way to validate the amount of pressure applied to the brake pedal, nor the timing of the pressure application.

Third, the brakes will slow the vehicle, shifting to neutral will stop the acceleration and the vehicle can be safely stopped.

Even if the transmission lever was stuck as well, you can still slow the vehicle and edge it into a guardrail, etc. to stop it, i.e. a controller crash at lower speed and controlled angle, not stupidly continue into crossing traffic endangering others.

I never made such a statement. I still maintain that driver incompetence is ultimately responsible for turing the situation into a fatality instead of a survivable crash.

Yes, all the focus on fuel economy (not efficiency), has led to safety issues.

I think outsourcing of software development for some vehicles to third world countries where a lot of people don't drive has led to some silly mistakes that programmers who have driven for years would never have made such as full throttle cruise control resume function (Ford).

See my other reply for what was misleading as usual from the loons at CR.

Yes, that "demo" provided no objective data. See my other post.

Neither of those quotes makes the claim you assert. "Controlled" and "slow" are the key words here and neither are synonymous with "stop".

Yes, and the CR "demo" provided no objective data to show the pedal force applied, it's timing, and correlation with vehicle speed, brake temperature, etc. It was misleading meaningless fluff.

Runaway vehicle ramps come to mind. Of course vehicles with manual transmissions also have useable engine braking.

I wouldn't trust anything coming from CR. They have proven to be anywhere from deliberately deceptive to utterly clueless in their various claims.

Sure they say that. Why couldn't the CR guy do it with a lesser HP Camry?

Maybe, but you don't know that. Looked like the CR guy put his foot down firmly, and the car kept going. Those brakes could have started fading bad and then burned up. We don't know because he put it in neutral. Too bad he didn't continue, but he didn't want to tear the car up. I don't know that anybody is really testing the "open throttle/brake on" scenarios, because the assumption is you'd just shut down or put in neutral when you get an open throttle condition.

BTDT - the old drums are not to be compared to discs. Besides fade they would fill with water if you drove through a deep puddle and you came out of the puddle with no brakes.

I was thinking about older discs versus newer. Don't even want to talk drums. Haven't kept up with who's using 4-wheel discs, but my cars still have rear drums. And wasn't thinking about the '60-70's, but more late '80 and forward. A quick look found this. About 4 years old though. Don't want to dig in because I'm not in the market for a car.

Quite a difference in stopping distance there. The Camry was probably fading hard on the first run. There's a reason for that, and it's most likely smaller rotors and pads. But that's a guess. Most people don't look for braking tests before they buy a car, and there can be quite a difference in stopping juice between cars that one assumes are essentially the same. I remember being surprised when reading test specs at how long it took to stop mid-90's Civics. Comparable to F-150's and Dodge Vans. And that can enter into whether your engine can overcome your brakes when your talking a lot of horses. Then there's the condition of the brakes to consider. I don't know how much pad wear was on the loaner Lexus, or if the rotors were shaved. None of this stuff is readily figured out except he couldn't shut it down by turning a key. That's the fatal flaw in the car.

--Vic

Read the article in the March Car and Driver on Camry stops under throttle-- saves a lot of speculation on distances.

bob

1. 102 reported incidents. Out of 2.3 MILLION vehicles.
2. "911" "our accelerator is stuck!" "What" "OUR ACCELERATOR IS STUCK!"

Had time to call 911, and talk to them, but couldn't think to shut the car off, or put it into neutral?

There are buses almost anywhere in the US. My suggestion is that people that can't think fast enough in emergency situations like that should by long-term bus passes.

People are too complacent in cars. It is a machine, and can be a dangerous machine. Too many people lose touch with that.

I remember on my way to work about 15 years ago, seeing some 20-something year old bimbo approaching a traffic jam, DANCING in the front seat with her hands off the wheel.

I really like seeing idiots like that on the road when I spend 4-8 hours a day in a car.

They made no claim that it provided objective data. I have seen no objective data provided by you.

This was discussed in a prior thread and at the time I tried doing a complete stop with full throttle and mashing the brake pedal from about 55 mph on a level road. I was surprised at how hard it was to stop the car. It was VERY difficult (I did not pump the pedal) and I had to apply much much more pressure then would normally be required and it took far longer to stop. The car had ABS and it was so hard to stop it that the ABS barely kicked in at the beginning of the stop, by the end the brakes were so hot they were not working well and the ABS wasn't needed because they weren't putting enough pressure on to even come close to skidding. I immediately got out and poked around the brakes and they were HOT, much hotter then normal driving would get them. And after that stop they felt glazed, that was a couple months ago and they are only now starting to feel "normal" again. It's a company car -- I would not recommend anyone do this with their own car as it will very possibly damage your brakes. If I had been going downhill at 65 and had pumped the brakes a couple times I would not be at all surprised to find that it was not possible to stop the car at full throttle. I think it's true that if you KNOW ahead of time and really mash the brake and hold it you probably can stop, but if it's an "oh shit" situation it may not work out so well.

There was nothing misleading about teh video. They made no claims that it was a rigorous test, they were simply showing what might happen in a typical situation, which is a lot more then anything you have seen produced by Toyota or anyone else so far.

On Tue, 02 Feb 2010 22:33:25 -0700, Ashton Crusher wrote:

I missed that, and the March Car and Driver "test" that somebody else posted about. So now I believe that the brakes will overcome the engine. If the brakes don't fail, and if you're not going down hill, and if you don't pump the brakes, and if you can maintain +150 pounds on the brake pedal. Okay, you met all the "if" conditions. Your car has finally stopped. You managed by some miracle get the front bumper against a big oak tree. Maybe ran over 18 pedestrians on the way, and you're missing 3 fenders. Grand Theft Auto. Now your leg is tired and you have to bail out. But you figure when you release the brake and bail, the car could jump sideways and crush you. A light bulb goes off in your head. You put your hand on the ignition key, and turn it. The engine shuts down and it's all quiet. You can hear the manifold ticking, your heart beating, and smell brake pads and sweat. Then you say to yourself, "Man, I handled that emergency well." Of course the whole damn scenario is absurd, since almost anybody would have gone for the key in the first place. If you had a key to turn. One thing I may have learned from the CR video is to find out if my car has a rev limiter. I don't think so. It's a '97 Lumina with a 3.1. My instinct for the open throttle scenario would be to go for the ignition key first. But it might be better to shift to neutral and shut down when stopped. The times I've had have any engine shut down underway are few, and never in heavy traffic. PS and PB were a bear, but manageable. My instinct might have changed from seeing that CR vid, but that depends on whether I have a rev limiter. Because another of my instincts is to avoid exploding engines.

--Vic

I don't know if this has been addressed before as I don't read each and every post, but are respondents ignoring the factor of rotational and other kinetic energy (in addition to the power produced by the engine alone) of a moving, high speed vehicle that is imposed on the braking system?