Motorists, experts say throttles to blame

[Gary Allan]

Quote:

But do we add all these electronic controls just for the simple reason "that we can".

Mostly. There are co-benefits that tend to cost more than they bring to the table ..but that's about it. It's not just limited to electronic controls. What sense is it to make a trans that gets .05 more mpg in the EPA economy cycle and provides the consumer DEMANDED "velvety smooth shifts" ..when it's failure costs more than the savings in fuel and renders the chassis unserviceable due to market value? What does a drive by wire system cost to replace/repair assuming it fails in the preferred default (non) FAIL SAFE mode? I think we'll find out just how much it cost to fix it now. I'd say the cost to Toyota ..and therefore every customer in the future, will be more than just running a cable. Innovation for its own sake is stupid. Fine for us hobby grade types ..but for people who already supposedly know what they're doing in a 'been there/done that" environment

 

[d00df00d]

Originally Posted By: jcwit

Dumb question and statement from an old gezzer who doesn't understand all this electronic stuff. But do we add all these electronic controls just for the simple reason "that we can".

All technology boils down to that, doesn't it?

 

[ekpolk]

Originally Posted By: tenderloin

. . . The average number of sudden acceleration complaints involving the Tacoma jumped more than 20 times, on average, in the three years after Toyota's introduction of drive-by-wire in these trucks in 2005. Increases were also found on the hybrid Prius, among other models. . . . [email protected] ralph.vartabedian @latimes.com http://www.latimes.com/business/la-fi-toyota-throttle29-2009nov29,0,1231630,full.story

Well, there's a clue that this "controversy" is, at least in part, driven by other motives. The Prius has always been a DBW car, and therefore, a claim that the Prius saw an increase in uncommanded acceleration after a "change" to DBW is totally and completely BOGUS. I don't like most of the current DBW setups (and I certainly didn't like the one on my 2003.5 V-6 Camry (I posted about that long, long ago...), but mistakes like this only serve to prove that such stories are being told by folks with an agenda other than disclosing actual problems with real world cars. Once the author's cred is blown, it's blown completely, and forever. BTW, I've now owned and extensively driven no less than four (4) Toyota DBW cars, and I've never experienced even a hint of uncommanded acceleration. In fact, my only complaint is that the Toyota DBW doesn't put the fat on the fire quickly enough. I wouldn't be surprised at all if the infamous paid liar Art Spinella is lurking in the background somewhere on this one (note, the immediately preceding statement, in this paragraph, is my OPINION, based upon the information that I have been able to derive from the quagmire commonly known as "the internet").

 

[PT1]

There is nothing wrong with ETC...Toyota simply has a component failure issue or a firmware issue in their system. They will get to the root cause and fix it since it definitely falls under the catastrophic failure category with NHTSA. They have no other choice. I have already received one letter from Lexus about it.

 

[Kestas]

I think emissions is a more important reason automakers went to ETC. I know that the puff of extra emissions during shifts with manual transmissions was a point of contention between the automakers and EPA.

 

[hone eagle]

Exatly -- emmisions, any cost is worth even a minute reduction same as milage .05 is worth any cost if it gets you below a threshold. My '99 diesel has it to prevent blacksmoke (mostly does)

 

[mpvue]

the DBW on my VUE was programmed to float the throttle between shifts; I supposed it was to make it easier to shift (it did, takes a bit getting used to when you are raised on traditional systems) but if they also did it for reduced emissions, well, they gotta do what they gotta do. the GM DBW systems have been around for a while, no issues. IIRC, when GM started doing this, they benchmarked a BMW 750il. BMW wouldn't sell them the drivetrain and DBW system, so they bought a whole car and put the whole drivetrain in a Caprice for testing! somewhere there is a Caprice running around w/ a BMW 12cyl under the hood.

 

[calvin1]

Originally Posted By: hone eagle

Exatly -- emmisions, any cost is worth even a minute reduction same as milage .05 is worth any cost if it gets you below a threshold. My '99 diesel has it to prevent blacksmoke (mostly does)

What irritates me is they'll take a big hit on mileage if it gives just a tiny improvement in emissions (safety too). This is the reason why the I4s & V6s of the 1990s were so much better on gas than what you can get now. They cut the compression just to get a little bit less NOx.

 

[d00df00d]

I always thought it was that cars are so much heavier now, and people want them to be more powerful. Either way -- and please correct me if I'm wrong -- I don't see how anything that would lower emissions could compromise fuel economy. It's all about more efficient combustion. If something reduces harmful byproducts but increases the fuel burned, how is that better in the end?

 

[calvin1]

Many of the recent increases in safety have come at the expense of more weight. Google the Carnot Theorem. The bottom line is that the hotter the fuel burn the greater the efficiency. The problem with that is Nitrogen will combine with Oxygen at those higher temps and form NOx. The only way to keep the temps down is by reducing compression and keeping the air/fuel mix rich. High compression and lean fuel mixes are good for mileage but bad for NOx emissions. When faced with that trade-off the EPA chose emissions over mileage.

 

[brianl703]

Running an engine lean causes an increase in NOx (oxides of nitrogen) emissions. So, fuel economy goes up, but NOx emissions do too.

 

[d00df00d]

I see. That seems to make sense. I remember reading about Mercedes AMG engines when they were 3-valve, and apparently part of the reason for only having one exhaust valve was to keep exhaust port temps up to decrease emissions. I assume that there is an optimal heat range to balance combustion efficiency with NOx production. Is then safe to conclude that those engines would have been on the other side of the optimal range had they been 4-valve?

 

[calvin1]

idk, they might have been trying to get the engine up to temp quicker to keep unburned HC down during cold start.

 

[Gary Allan]

Quote:

There is nothing wrong with ETC Toyota simply has a component failure issue or a firmware issue in their system.

If this was steer by wire I'd have a hard time saying that nothing is wrong with the concept when ever anything went wrong with it. While you can and will have mechanical failures in regards to steering, it would take the most obscure event to provide absolutely no warning to the operator of such failure. It could also produce like anomalies as this Toy full throttle problem and send your car going in circle @ 80mph ..or any which way it pleases. Would your "Eh " response to this issue be so casual if that type of failure occurred?

Quote:

I think emissions is a more important reason automakers went to ETC. I know that the puff of extra emissions during shifts with manual transmissions was a point of contention between the automakers and EPA.

They could have ignored it for the amount that it contributed to total emissions ..or managed it from another angle. I'm figuring something like a morphed throttle stop technology governed by limits set with the mechanically actuated throttle ..that is the mechanical enabling the response limits of the throttle motor. Obviously this technology doesn't have fail safes incorporated into it and is probably the most potentially dangerous use of operator disconnect from the vehicle with the exception of the aforementioned steer by wire. Again, you can't use air liners and whatnot as a standard. They're not operated multi-million times a day ..every day and have a whole lot more put into them than some bid job bean counter lowball part.

 

[PT1]

Originally Posted By: Gary Allan

If this was steer by wire I'd have a hard time saying that nothing is wrong with the concept when ever anything went wrong with it. While you can and will have mechanical failures in regards to steering, it would take the most obscure event to provide absolutely no warning to the operator of such failure. It could also produce like anomalies as this Toy full throttle problem and send your car going in circle @ 80mph ..or any which way it pleases. Would your "Eh " response to this issue be so casual if that type of failure occurred?

The first generation steer by wire systems had huge issues with oversteer in Europe before they were released into the mass production domestic market. Many vehicle rollovers due to problems with steering feedback. The suppliers got it fixed. My response is not casual as I happen to own 3 Toyota vehicles all equipped with ETC. (one is a 08 Lexus ES350). But I am not advocating going back to throttle cables. That's all. The ETC concept is better IMO, Toyota simply has an issue with their system. Could be as simple as a component failure, wire harness failure, firmware etc. I am also not afraid of my vehicles either as I have tested my ES for shutdown at WOT and indeed it does shut down. Statistically speaking this is an issue that needs immediate attention but no more life threatening than H1N1 or the H1N1 vaccine IMO. Bottom line: 1.Am I going to trade in my Toyota vehicles or stop driving them: No. 2.Have I instructed all the drivers in my household what to do if the ETC goes haywire: Yes. 3.Do more drivers suffer fatal accidents from worn or underinflated tires every year?: Yes. 4.Do more drivers die in SUV rollovers every year?: Yes. 5.Does the media cover fatal tire failures?: Not since the Ford Explorer incidents. I just refuse to panic over the whole situation. Like Bogey says: "Ya pays your money and ya takes your chances"

 

[eljefino]

Originally Posted By: calvin1

Many of the recent increases in safety have come at the expense of more weight. Google the Carnot Theorem. The bottom line is that the hotter the fuel burn the greater the efficiency. The problem with that is Nitrogen will combine with Oxygen at those higher temps and form NOx. The only way to keep the temps down is by reducing compression and keeping the air/fuel mix rich. High compression and lean fuel mixes are good for mileage but bad for NOx emissions. When faced with that trade-off the EPA chose emissions over mileage.

This is a fairly large ripoff by "the man" and bears repeating. We should normalize with European standards if a car manages, say, 42 MPG highway, and the purchaser signs a waiver acknowleging they're tinny "deathtraps." Alternatively, since NOx are an issue in LA's smog bowl but that's about it... we could broadcast a radio subcarrier or use a GPS receiver that "frees" an engine to be more efficient eslewhere. But that would step on the wrong toes and would be unlikely to happen.

 

[brianl703]

NOx is also an issue in the DC area. The Feds have threatened to cut off highway funding if it's not brought under control.