**** Consumer Warning **** - The Flip Side of the Perfect Prius

[Rich Parsons]

The Flip Side of the Perfect Prius

Is the title of the article found here: http://www.seattleweekly.com/2009-04-22/news/the-flip-side-of-the-perfect-prius/1


Some highlights:

Sometimes the cars accelerate on their own. Sometimes they stop dead. Drivers of the hybrid Prius have discovered they can be an unexpected adventure.

Traffic near the mall was congested but moving, and Riner kept the Prius pegged at 60 mph, constantly looking at the console to manage her fuel consumption.
Suddenly she felt the car hydroplaning out of control, and when she glanced at the speedometer she realized the car had shot up to 84 mph. Riner wasn't hydroplaning; quite simply, her Prius had accelerated on its own.

Now another side of the Prius has orbited into view, as owners share horror stories on blogs and message boards about crashing their cars through forests, garage doors, and gas stations.

Stories from other Prius owners involving unintended acceleration are fairly common, and one of the first places to publish them was the Web site www.consumeraffairs.com, which each day collects about 400 complaints that are read by editors and stored in an online database.

There are lots of things to quote in the article.

 

[Nolerama]

I read that same article in the Riverfront Times here in STL.

I don't care how marginal the cases may be, if a car is known to accidentally accelerate on its own, then I'm not buying it.

If people are going to be environmental, ride a bicycle to work at least once a week, or car pool, or public transit.

Buying more metal/plastic isn't the solution to saving natural resources/environment.

 

[Sukerkin]

On top of that, it has been illustrated on Top Gear that, when driving at normal road speeds, you get better MPG out of a BMW M3! Plus you don't have your car registered as toxic waste when it comes time to dispose of it.

The Prius is a stepping stone along the route to a non-petrol driven car, not a single-handed saviour of the environment or, so it now appears, your insurance premiums (or worse) .

 

[jim777]

I'll do what I can for the environment and try and get my wife's permission to get that M3 when my current '95 Camry dies

 

[Tames D]

Suddenly I don't feel guilty about owning a couple of gas guzzlers.

 

[CuongNhuka]

On top of that, it has been illustrated on Top Gear that, when driving at normal road speeds, you get better MPG out of a BMW M3! Plus you don't have your car registered as toxic waste when it comes time to dispose of it.

The Prius is a stepping stone along the route to a non-petrol driven car, not a single-handed saviour of the environment or, so it now appears, your insurance premiums (or worse) .

A better stepping stone would be Deisel engines. Hre is a few quotes form a Deisel repair manual I have to explain:

Diesel fuel comes from a lower petroleum distallate than gasoline and it lubricates the fuel pump and injectors, reducing wear in the engine. The cetane number of diesel indicates it's ignition quality; the higher the number, the faster it burns, making for easier starting and smoother running. Diesel feul contain more energy and burns more air per volume than gasoline which partially accounts for diesels greater effeciency.
There are however, several disadvantages to diesel fuel. It contains more paraffins (waxes), it's volatility is affected by temperature more than gasoline is, it absorbs moisture readily and it contains ten times more sulfur than gasoline. At lower temperatures (10 degrees F and below) number two Diesel fuel will crystallize, clogging the feul filter. If cold enough, the fuel cann't be poured or pumped ("pour point"), so different blends of fuel are required for summer and winter driving.
.....
Diesel engines offer sever advantages over gasoline engines, particularly in the area of fuel efficiency, low speed torgue and reliability. One of the reasons diesel fengines tend to get better mileage than gasoline engines is because they burn fuel more completely. Diesel fuel exhaust, when the engine is properly tuned, actually have fewer hydrocarbons and carbon monoxide than gasoline exhaust

There are some easy to solutions to the listed problems. You can have the engine 'winterized' which would reduce how easily the fuel freezes (for lack of a better term). Winterization is a common thing in colder enviroments (like Alaska and part of Canada). Increased sulfur just means that you would have to get the engined serviced a little bit more.
Also, a diesel engine will run on used cooking oil for just the addition of an added filter, and it's only slightly less effecient. But, because is more effeceint then a gasoline anyways, it would balance out in the end.

 

[Sukerkin]

I'm not going to dispute that there are certain efficiences associated with a properly tuned and maintained diesel engine - however, I'm one of those 'evil' performance car and motorsport buffs, so the only reason why I am in favour of any alternatives to petrol for daily driving is so that we have more petrol left for the sports cars .

Okay, some of the above may not be totally true ... can you guess which bits ?

 

[CuongNhuka]

Crap, too late to edit. I just realised how part of my post read.

While you can run a diesel engine on straight vegitable oil (even used oil), it would destroy your engine before long. There are three companys who do little other try to find cheap effeicent ways to make cooking oil into biofuels. Everything they have come up with so far is largely experimental, as there are no long term studies into the effects these biofuels have on the engine.

Moral of the Story: If you plan on converting your car into a biodeisel machine: DO LOTS AND LOTS OF RESEARCH!!!!!!!! And don't even bother unless you have a signifficant understanding of chemical enginering, mechanical engineering, and know the every detail of how a diesel engine works.

 

[Jenna]

I'm not going to dispute that there are certain efficiences associated with a properly tuned and maintained diesel engine - however, I'm one of those 'evil' performance car and motorsport buffs, so the only reason why I am in favour of any alternatives to petrol for daily driving is so that we have more petrol left for the sports cars .

Okay, some of the above may not be totally true ... can you guess which bits ?

Mmmmm You need to be petite to get in that cockpit. I will happily take the 997 though
Jenna

 

[Sukerkin]

To misquote Al Murray, something for the lady:

{whispers}Pick the green one !{/whispers}

 

[Jenna]

To misquote Al Murray, something for the lady:

{whispers}Pick the green one !{/whispers}

Ooooh baby... that is pure pr0n I am not sure how you circumvented the filters Suke! Thank you my friend I would have a nightful of comforting dreams ahead in which I am £70K happier and not just 3pts from disqualification!
Jenna

 

[Rich Parsons]

A better stepping stone would be Deisel engines. Hre is a few quotes form a Deisel repair manual I have to explain:



There are some easy to solutions to the listed problems. You can have the engine 'winterized' which would reduce how easily the fuel freezes (for lack of a better term). Winterization is a common thing in colder enviroments (like Alaska and part of Canada). Increased sulfur just means that you would have to get the engined serviced a little bit more.
Also, a diesel engine will run on used cooking oil for just the addition of an added filter, and it's only slightly less effecient. But, because is more effeceint then a gasoline anyways, it would balance out in the end.

First I agree that Driving at high way speeds is not what the Prius is designed for. The GM system also used by some Chrysler programs, allows for the motors to be disconnected and run a straight over drive in top gear.


As to Diesel, I agree it adds a lot to fuel economy. The problem has been emissions. Europe has had lack emissions on Diesels with higher gas tax on regular petro (* unleaded gas here in the states *), but that is changing. The problem is that once you put $3k to $6k in Exhaust treatments onto a vehicle the return fuel economy is hurt by the up front cost.

SHHH!!! I know the same is true for the Hybrid Battery and Motor costs for the extra fuel economy.

 

[CuongNhuka]

First I agree that Driving at high way speeds is not what the Prius is designed for. The GM system also used by some Chrysler programs, allows for the motors to be disconnected and run a straight over drive in top gear.


As to Diesel, I agree it adds a lot to fuel economy. The problem has been emissions. Europe has had lack emissions on Diesels with higher gas tax on regular petro (* unleaded gas here in the states *), but that is changing. The problem is that once you put $3k to $6k in Exhaust treatments onto a vehicle the return fuel economy is hurt by the up front cost.

SHHH!!! I know the same is true for the Hybrid Battery and Motor costs for the extra fuel economy.

Actually, if you re-read my first post, you'll see that Deisel has less Hydrocarbons and Carbon Monoxide. If you're woundering, thats a Hynes tech manual.

 

[Carol]

Generally I am skeptical about "unintentional acceleration" claims. Google around and one can find such claims about a lot of cars. Perhaps I'm just a pessimist but I think most of them are borne from people trying to find some way to avoid a surcharge issue with their insurance after getting in to an accident. The Prius is a popular car. There are many on the road and all it takes is a story or two online for the idea of an "unintentional acceleration" claim to spread.

I'm not an expert on the Prius, I don't even like the car. But these claims don't make sense to me. The Prius, like most hybrids, uses two different braking systems. It has regenerative braking to generate electricity. This is kind of like the effect that you would experience if you were on an exercise bike and suddenly turned the resistance way up. Pressure on the bake pedal engages a generator that puts a lot of resistance on the forward motion, and generates electricity. The Prius doesn't rely solely upon this for braking, it also has conventional brake pads.

Most cars nowadays have power brakes, however...in the unusual event that a car loses its electrical system, the brakes can still be applied with a bit of force. My own car can still brake even the engine and electrical system goes dead...something I learned this winter when the ice storm took out a couple of sensors in my own car, causing it to stall at a couple of inopportune times

Generally "unintentional acceleration" claims, including these, are accompanied with claims that the brakes didn't work. I did a bit of googling and folks are claiming exactly that. The brakes didn't work. The e-brake didn't work. I find it hard to believe that if the electrical system goes dead then the driver has absolutely no stopping power by hitting the brake pedal. I find it even harder to believe that if the electrical system goes dead, then the driver's e-brake will also fail. I also find it hard to believe that Toyota would release a car to the U.S. market that would lose all braking ability in the event of an electrical failure.

However, I am willing to be proven wrong if there is sufficient data. :asian:

 

[CuongNhuka]

Generally "unintentional acceleration" claims, including these, are accompanied with claims that the brakes didn't work. I did a bit of googling and folks are claiming exactly that. The brakes didn't work. The e-brake didn't work. I find it hard to believe that if the electrical system goes dead then the driver has absolutely no stopping power by hitting the brake pedal. I find it even harder to believe that if the electrical system goes dead, then the driver's e-brake will also fail. I also find it hard to believe that Toyota would release a car to the U.S. market that would lose all braking ability in the event of an electrical failure.

Its pretty much impossible for someones breaks to fail on a conventional system. Even with power brakes and anti-lock brakes. There is only a couple ways for this to happen. The brake line is cut, which would be really noticeable, since there would be a large puddle of brake fluid on the ground, and you would notice that your brakes are getting spongier and spongier (if you're driving in the city). Other then that, I think the only way would you had no brake pads. :erg:
If you had air in the lines, it might appear that your brakes out, but that would only be if you slammed on the brakes, and lifted off. I cann't think of why someone would do that.

Whenever someone says there brakes are out (atleast with Marine Corps Equip) the first thing checked is the brake lines. If that is not the case, the mechanic has to file a report with the PMO (military police). Odds are, the op. destroyed something, so the cops have to find out that he probably screwed up.

 

[Carol]

Its pretty much impossible for someones breaks to fail on a conventional system. Even with power brakes and anti-lock brakes. There is only a couple ways for this to happen. The brake line is cut, which would be really noticeable, since there would be a large puddle of brake fluid on the ground, and you would notice that your brakes are getting spongier and spongier (if you're driving in the city). Other then that, I think the only way would you had no brake pads. :erg:
If you had air in the lines, it might appear that your brakes out, but that would only be if you slammed on the brakes, and lifted off. I cann't think of why someone would do that.

Whenever someone says there brakes are out (atleast with Marine Corps Equip) the first thing checked is the brake lines. If that is not the case, the mechanic has to file a report with the PMO (military police). Odds are, the op. destroyed something, so the cops have to find out that he probably screwed up.

Thanks very much. And big thanks for your service! :asian:

 

[Rich Parsons]

Actually, if you re-read my first post, you'll see that Deisel has less Hydrocarbons and Carbon Monoxide. If you're woundering, thats a Hynes tech manual.

And if you were an engineer you would know that just quoting a manual is not enough to understand.


Carbon particulates!

Sulfur which leads to SOx before reduced Sulfur Diesel was the standard. But reduced standard is not zero , which is why they have Sulfur traps.

So maybe you should go to school or read some more regulations or maybe read the parts on the vehicle.

Ans yes, if you put all this extra parts on the vehicle the emissions can be lower, but the cost makes it prohibitive.

Which was my point if you had read my post and not just looked to be argumentative.

 

[Rich Parsons]

Generally I am skeptical about "unintentional acceleration" claims. Google around and one can find such claims about a lot of cars. Perhaps I'm just a pessimist but I think most of them are borne from people trying to find some way to avoid a surcharge issue with their insurance after getting in to an accident. The Prius is a popular car. There are many on the road and all it takes is a story or two online for the idea of an "unintentional acceleration" claim to spread.

I am skeptical as well as there can be many reasons from driver error and or driver error to design flaws.

Driver errors include getting mats stuck as mentioned by the article.

They also include the person hitting the gas and brake at the same time.

But every now and then there comes along another reason that can be scary.

I'm not an expert on the Prius, I don't even like the car. But these claims don't make sense to me. The Prius, like most hybrids, uses two different braking systems. It has regenerative braking to generate electricity. This is kind of like the effect that you would experience if you were on an exercise bike and suddenly turned the resistance way up. Pressure on the bake pedal engages a generator that puts a lot of resistance on the forward motion, and generates electricity. The Prius doesn't rely solely upon this for braking, it also has conventional brake pads.

Carol,

The basic system for the Prius is Engine then Electric Motor then transfer to wheels through the axles and the "motors" used to regen as you stated.

If the motor sends too much torque to the wheels then the tires can squeal and the brakes smoke as the Electric Motor over comes the Brake and the drag force of the brakes and the fluid dynamic assistance or electrical assistance depending upon the design.

It could be other designs as well.

Most cars nowadays have power brakes, however...in the unusual event that a car loses its electrical system, the brakes can still be applied with a bit of force. My own car can still brake even the engine and electrical system goes dead...something I learned this winter when the ice storm took out a couple of sensors in my own car, causing it to stall at a couple of inopportune times

Yes Mechanical Override is designed to stop the system from moving. Or to keep the speed form getting away too fast, but, if the brakes are electronic and I cannot confirm in this case, and you brake by wire similar to throttle by wire (* aka ETC *) then you may not have a solid braking system. If it is a mechanical system (* Which I would expect is the design *) and it is designed to be able to stop the vehicle as you described in the case of loss of power, but it may not be designed to over come the power of electric motor.

Generally "unintentional acceleration" claims, including these, are accompanied with claims that the brakes didn't work. I did a bit of googling and folks are claiming exactly that. The brakes didn't work. The e-brake didn't work. I find it hard to believe that if the electrical system goes dead then the driver has absolutely no stopping power by hitting the brake pedal. I find it even harder to believe that if the electrical system goes dead, then the driver's e-brake will also fail. I also find it hard to believe that Toyota would release a car to the U.S. market that would lose all braking ability in the event of an electrical failure.

If you have a mechanical failure that prohibits the brake pads from engaging the drums or the rotors then one could not have brakes.

As to e-brakes this is usually a mechanical link that engages and is designed to stop the car from rolling by gravity on a certain degree hill. Yet they are not designed to stop the vehicle under power. They may, and some of the older ones could cause a momentary lock up which would allow you to execute a BOOTLEG turn around if done in reverse at the proper time of the turn around. Modern e-brakes will drag on set of brakes usually the rear and this can cause the brakes to smoke or squeal, but as 60 to 80 % or braking depending upon design is executed from the front brakes which are not locked up the power of the system can overcome it.

** WARNING - If you try to test your e-brake at speed, be prepared to pay for repairs as springs or locking pins could be damaged. **

However, I am willing to be proven wrong if there is sufficient data. :asian:

I would like to see data as well, such as trace data form an airbag module or some other controller from a vehicle that actually had a crash. To see what the gas pedal value was and the brake pedal and throttle angle and also the engine torque and in many cases steering angle to know if they tried to avoid an obstacle.

 

[Carol]

Thank you very much, Rich! :asian: Very interesting and informative.

I have a couple other questions for you about hybrids...but since they aren't about the Prius perhaps its best if I ask them in another thread.

 

[Rich Parsons]

From this article:

http://www.consumeraffairs.com/news04/2007/09/toyota_prius_mats.html

Toyota Recalls Floor Mats, NHTSA Warns Prius Owners

Not all Priuis owners buy the floor mat theory


By Joe Benton
ConsumerAffairs.com
September 27, 2007

The Toyota Motor Corp. and the National Highway Traffic Safety Administration (NHTSA) have agreed that faulty floor mats are the cause of runaway acceleration in the Toyota Prius hybrid as well as several other Toyota vehicles.

...
At the same time, NHTSA is strongly urging owners “make sure the driver-side, all weather floor mat is properly secured before driving the vehicles.”
NHTSA and Toyota noted that, if unsecured, the mats being recalled can slip forward and trap the accelerator pedal, causing the vehicle to accelerate uncontrollably.
...