Toyota's runaway-car worries may not stop at floor mats-LA TIMES

[Shawn Clark]

Originally Posted by Rybold

I hope the CHP officers boycott Toyota. Why do I say such harsh words? Because SAFETY should ALWAYS come FIRST!

I hope the CHP boycott's Toyota too. Their officers are apparently too friggin' stupid to drive them, and the rest of us don't need the total bullshit hysteria that the CHP are capable of generating.

Cripes, when will this absolute nonsense end???

[patsparks]

No danger of accidentally locking the steering on a Prius, there is no steering lock.
What about that Corolla? When my Prius glides, the engine is off but all the ancillaries still work, what about the Corolla?

My choice, move to neutral, maintain power steering and brakes. Not that I have ever or will ever need this.

[bwilson4web]

Originally Posted by Rybold

. . .
A huge deal-breaker for me in the 2010 Prius is the fact that you can't just shift into neutral and back to drive. . . .

This is a plot of four runs, GPS recorded data, of high speed, pulse and glide versus the equivalent, cruise control speed. The glide was effected by holding "N" for ~1 second. The pulse happened by shifting into "D" and hitting cruise control resume. You have to hold it in "N" for one second and shifting into "D" works every time with my 2010 Prius.

Now if you press and hold "Power" for 3 seconds, the car will shutdown and you will have to come to a complete stop to start it again. I do not recommend using "Power" unless "Neutral" fails ... so far, "Neutral" works every time.

Bob Wilson

[Rybold]

I went and test drove the 2010 Prius today and it shifted between drive and neutral, no problem. I don't get it. When I test drove the 2010 Prius about a month ago, it would not shift back into drive unless the car was at zero mph. Two different Toyota dealers, two different Priuses, and two different results.

Originally Posted by F8L

You can do the exact same thing in the Prius unless you are in warm up mode or have the AC/Heater on full blast.

Perhaps this is the variable.

Originally Posted by fuzzy1

a bad idea because of the risk of overspinning MG1 above 45 ?? mph.

Thanks for the info. "45" is the magic number then. I rarely shift into neutral above 45 anyhow, it's usually sub-45 that I shift into neutral.

Originally Posted by fuzzy1

As F8L points out, Neutral gains nothing on the Prius. Unlike a traditional transmission, mechanically there is nothing in the Prius that can be disengaged. The only disengagement is electrical, shutting off the motor and generator functions.

Makes sense. Since I don't own a Prius (yet?), I can't experiment with it. When you shifted into neutral, did you notice any change in resistance? For example, in my Corolla, when I shift into neutral, from engine braking, there is an obvious reduction in resistance and the car coasts/glides much further.

Originally Posted by fuzzy1

If the wheels turn, MG1 must still spin as dead weight at whatever speed it is forced by the MG2 (wheel) and ICE shafts of the HSD.

Again, same question: can you feel a difference in resistance when shifting between drive and neutral? Also, and this is a question for an electrical engineer (or anyone who has experimented and learned on their own), is there a difference in resistance whether a generator is hooked to electrical wires or not hooked up?

Originally Posted by fuzzy1

If you want to eliminate Prius's small 'fake engine drag' when coasting, just press the gas pedal slightly until the bar on the HSI display vanishes. The desired point is sticky, it will snap to that condition if you get and stay close, so precision dexterity on the pedal is not required.

Excellent. Problem solved?

Originally Posted by F8L

You can either put it in neutral OR simply let off the throttle then lightly reapply a little bit of pressure to disengage the regenerative braking and you will coast or as we call it, glide. You can go pretty damn far just gliding and after a few tries gliding becomes second nature and is easier than shifting in and out of neutral. I wish you were closer so I could take you for a ride and show you how it works. Then you could volunteer for my organization too.

Thanks!

Originally Posted by patsparks

No danger of accidentally locking the steering on a Prius, there is no steering lock.
What about that Corolla? When my Prius glides, the engine is off but all the ancillaries still work, what about the Corolla?

The powersteering runs out of pressure after about fifteen seconds. This is not a problem for me. The truck that I learned to drive in did not have power steering at all. We had to use these things on our arms called muscles. The reason I leave the engine running in my Corolla? After about 30 seconds, the power brakes run out of pressure.
.

And here's the money question: You are driving over a patch of ice or very slick road and want as little resistance as possible. In a traditional car, you would either disengage the clutch or shift into neutral. Will "glide" on the Prius offer as little resistance as neutral? (from an intuitive standpoint; not a "I hooked up twenty sensors and computers" standpoint)

This actually brings up another question: In my Corolla, I often shift into neutral before going down a steep grade or braking in the rain. The reason for this is that the Corolla transmission, with only four gears and wide gear ratios, the car jerks when downshifting downhill. As a precaution, to prevent the jerk (and potential loss of traction), I disengage the transmission before it has a chance to create a problem. If I am correct, the Prius does not have a transmission. The engine is directly coupled to the drive shaft and a powerful motor assists the engine at low speeds. But even then, does regen ever create a problem while braking downhill ?

Originally Posted by qbee42

Not me. My Prius fob never comes out of my pocket, except when I put my keys away at night. Tom

Schlage (available at Home Depot) now makes keyless entry for houses.

Originally Posted by bwilson4web

shifting into "D" works every time with my 2010 Prius. ... I do not recommend using "Power" unless "Neutral" fails ... so far, "Neutral" works every time. Bob Wilson

Thanks!
(responding to the graph, something that we discussed in another thread, was that at 52.5mph, wind resistance is significant enough that constant velocity is more efficient (due to greater wind resistance (F=-kx^2) while pulsing above 52.5mph); however while coasting from 30mph to 0mph, wind resistance is low enough that pulse and glide prevails (due to the fact that you can glide for much longer due to minimal wind resistance causing the vehicle to decelerate compared to the rate of deceleration at freeway speeds). And yes, I know very well that everyone here already knows this. I just felt like typing it so I can feel special. haha.
.

[Doc Willie]

LA Times follow-up: the plot thickens.

[qbee42]

Originally Posted by Rybold

I went and test drove the 2010 Prius today and it shifted between drive and neutral, no problem. I don't get it. When I test drove the 2010 Prius about a month ago, it would not shift back into drive unless the car was at zero mph. Two different Toyota dealers, two different Priuses, and two different results.

You must have done something different. They all work this way. It's not speed related.

Again, same question: can you feel a difference in resistance when shifting between drive and neutral? Also, and this is a question for an electrical engineer (or anyone who has experimented and learned on their own), is there a difference in resistance whether a generator is hooked to electrical wires or not hooked up?

Hooking a generator to wires does not increase the load. Drawing power from a generator increases the load. For example, plugging a light into the wall socket does not increase your electrical bill. Turning on the light after it is plugged in *will* increase your bill.

As for the Prius, feeling a difference between drive and neutral all depends on the load in drive. In neutral there is no load, other than drag and parasitic losses. In drive, if you feather the gas pedal to avoid acceleration and regenerative braking, it feel exactly as it does in neutral.

And here's the money question: You are driving over a patch of ice or very slick road and want as little resistance as possible. In a traditional car, you would either disengage the clutch or shift into neutral. Will "glide" on the Prius offer as little resistance as neutral? (from an intuitive standpoint; not a "I hooked up twenty sensors and computers" standpoint)

You can do this with the Prius, but there is no need for it. The Prius control system is smart enough to do the modulation for you. My Gen II Prius with VSC is the most stable winter car I have ever driven, including a Jeep C-J5, a 4wd Subaru, and a Ford Aerostar van with electronic 4wd.

This actually brings up another question: In my Corolla, I often shift into neutral before going down a steep grade or braking in the rain. The reason for this is that the Corolla transmission, with only four gears and wide gear ratios, the car jerks when downshifting downhill. As a precaution, to prevent the jerk (and potential loss of traction), I disengage the transmission before it has a chance to create a problem. If I am correct, the Prius does not have a transmission. The engine is directly coupled to the drive shaft and a powerful motor assists the engine at low speeds. But even then, does regen ever create a problem while braking downhill ?

No, regen never creates a problem braking downhill. It makes things a lot better, since it saves wear and tear on the friction brakes. The Prius also features an engine braking mode, called "B mode", which is like downshifting with a normal transmission. B mode is very nice for mountain roads.

Tom

[philobeddoe]

* Jean Bookout awoke in an Oklahoma hospital a month after a crash in her 2005 Camry.

She said the car sped out of control on a freeway, then smashed into an embankment after she swerved it onto an exit ramp, leaving behind long skid marks from attempts to stop the vehicle with her brakes and emergency brake.

Bookout sustained permanent memory loss, and her best friend died.

"I did everything I could to stop the car," she said Tuesday.

* Nancy Bernstein, a vice president for a Long Beach community garden and former science teacher, said she was taken on an 8-mile high-speed ride by her 2007 Prius while she was following her husband in a group bicycle tour in Wisconsin. She said her Prius accelerated from 45 mph to 75 mph on a winding, two-lane highway crowded with 100 cyclists.

"I was sure I was going to kill someone on a bicycle or myself," she recalled. "I stood on the brakes with both feet. All of a sudden, I see fire. I thought, sure, my brakes are on fire. I thought about maybe trying to sideswipe a tree to slow down."

Eventually she was able to stop at the bottom of a hill, using her brakes and emergency brake. A local resident rushed out with a fire extinguisher.

* Dr. David. W. Smith, an emergency room physician from San Dimas, has yet to receive a satisfactory answer from Toyota about his Lexus GS 300. Smith said he was driving with his cruise control in Central California on Highway 99 last year, not touching the accelerator, when suddenly the vehicle accelerated to 100 mph.

The brakes did not release the cruise control or slow down the vehicle, Smith recalled. Finally, he shifted into neutral and shut off the engine. "I am sure it is the cruise control," he said. "I haven't used it since."

As for its position that brakes can always overcome a vehicle's engine, the safety agency and Toyota now acknowledge that a braking system cannot always counter a wide-open throttle, as is the case in sudden acceleration.

It would be great if one of these media outlets could solicit an expert opinion to suggest what a driver should actually do in the event of one of these rare and inexplicable episodes

the idea that someone would sit in their car doing nothing but stand on the brakes as the car uncontrollably accelerated is mind boggling

i can understand that there may not be enough time and input for someone to realize that by mashing on the brakes they are actually flooring the accelerator

but sweet jesus, can't the LA Times at least put in a blurb that says SHIFT TO NEUTRAL or are they worried about liability?

[fuzzy1]

Qbee already answered most of the questions directed to me, but here is a bit more. See also the Transmission Question thread for more info about what happens in Neutral.

Originally Posted by Rybold

When you shifted into neutral, did you notice any change in resistance? For example, in my Corolla, when I shift into neutral, from engine braking, there is an obvious reduction in resistance and the car coasts/glides much further.

When shifting with foot off the throttle, i.e. it was in 'fake engine drag' mode, yes, there is a noticeable reduction in resistance. But I don't remember it being any better than what is achieved by using the pedal to make the HSI power bar vanish.

On your Corolla, much of the in-gear drag is engine compression braking, also known as pumping loss. When the engine is idling, the pistons pull air past the nearly closed throttle plate, creating a strong vacuum. This process consumes a lot of power, causing a lot of drag, and is an inherent loss mechanism in traditional (Otto cycle) gas engines. The loss is also proportional to engine RPM and displacement, which is why bigger engines are bigger fuel hogs.

The Prius uses an Atkinson cycle, which effectively means that its variable intake valve timing produces a variable displacement. When 'Idling', its valves are set for minimum displacement, and the transmission lets it spin at minimum speed (0 rpm when rolling at 0-45 mph, 992 rpm when rolling 46+ mph). Both factors give it a big advantage over your Corolla.

Also, and this is a question for an electrical engineer (or anyone who has experimented and learned on their own), is there a difference in resistance whether a generator is hooked to electrical wires or not hooked up?

I am an electrical engineer. And as Qbee noted, a generator's shaft does see resistance proportional to the load drawn out of the electrical terminals, in addition to some friction loss.

[fuzzy1]

Originally Posted by Doc Willie

LA Times follow-up: the plot thickens.

From the LA Times article ...

The crashes resulted in at least 19 deaths and scores of injuries over the last decade, records show. Federal regulators say that is far more than any other automaker has experienced.
...
In a written statement, the NHTSA said its records show that a total of 15 people died in crashes related to possible sudden acceleration in Toyota vehicles from the 2002 model year and newer, compared with 11 such deaths in vehicles made by all other automakers.
...
In 2008, the NHTSA opened a probe of the Toyota Tacoma after a consumer found that the truck had accumulated 32 times as many sudden-acceleration complaints as any other pickup

Earlier I asked whether or not Toyota suffered more of these incidents than other brands. These comments appear to be a direct answer.

As for its position that brakes can always overcome a vehicle's engine, the safety agency and Toyota now acknowledge that a braking system cannot always counter a wide-open throttle, as is the case in sudden acceleration.

This directly challenges the many claims that brakes can always overcome the engine. The CR video at ABC News even demonstrates this problem. CR make no reference to this possibly being linked to the adoption of ABS, forcing brake overheating, as some have claimed here.

...Smith recalled. Finally, he shifted into neutral and shut off the engine.

From the CR video -- "Most people have never put their car into Neutral".

This statement flabbergasted me. I must be getting really old.

How few minutes, besides 'not enough', does Driver Education take these days?

[DeadPhish]

Originally Posted by Doc Willie

LA Times follow-up: the plot thickens.

There is nothing new here. The prior incidents were investigated by the NHTSA going back to 2002 as the article said. The article quotes the NHTSA stating that 'no evidence was found....' That's why they closed the cases.

The other key point is that the ones who are paying for these crashes, deaths, injuries and damages also are absolutely silent on the matter. The insurance companies have not issued one word on any of these issues. It's the insurance companies and their pit bull the IIHS that would have a vested interest in making these accidents disappear if there was a technology issue causing it. The IIHS has never been hesitant to get on GMA or the Today Show and promote one safer vehicle or technology over another. If there was such a problem and there was a solution to such problem the IIHS would be duty-bound on behalf of its pricipals to broadcast both.

Thus since 2002 and over 20 million vehicles the 'reports' of alleged unintended acceleration are all unsubstantiated or if true the cause is unknown. All of them. This is the key fact IMO.