GM says Two Mode Hybrid System Trumps Competition

If you have anything to the point to say, say it.

OT: I swear, this is like a Macintosh usenet group: say one thing slightly critical about the Holy Object, and you are instantly shouted down as a "troll." No, I take that back: this is even worse than a Mac group; after all, I haven't said anything critical about the Golden Calf; instead, I have failed to sing Its praises loudly enough to suit the faithful!

Have I stumbled upon a cult, here?

 

"The "State of the Hybrid Nation" article"

Did you read it? I just did. I had to chuckle when I got the part that said most automotive engineers agree that adding hybrid technology to a given vehicle improves fuel efficiency by about 25%.

 

They couldn't have been much more misleading. Generic use of the word "hybrid" is just plain wrong. Please don't encourage that.

There are several different technologies that improve fuel efficiency. They obviously don't all work exactly the same way. Original Prius, Classic Prius, HSD Prius, GT Prius, and Escape-Hybrid are all "full" hybrids. Yet each has a different efficiency percentage. That's also true for the 3 generations of Honda hybrid technology. And the "two-mode" technology from GM is likely to be different as well.

A single number like 25% is clearly inappropriate, just as generalizing about what "hybrid" means.

 

'A single number like 25% is clearly inappropriate, just as generalizing about what "hybrid" means.'

Oh, I know that. But I had to laugh all the same, given the context of the discussion. And obviously, a layperson's estimate of the efficiency gains provided by any given techonology is hampered by the inability to conduct controlled experiments. Instead, we are reduced to rough estimates based on "similar" production cars. Compared to a Hummer 1, the Prius's fuel economy looks wonderfully like something out of Star Trek; compared to the now-extinct EV-1, the Prius looks like a gas guzzler. When Toyota gets around to offering a car with "trim" lines similar to Honda's new Accord line (say, a Highlander line including vehicles with and without HSD), then we'll have a much better idea of how effective HSD really is.

 

<div class='quotetop'>QUOTE(DanP\";p=\"61061)</div>

Sorry about that. Never mind that last post. I searched back through the posts and found the link I think you're talking about: the bar chart with "vehicle efficiency" and "fuel efficiency" expressed in percentages. It's still not clear what "vehicle efficiency" is (or "fuel efficiency", for that matter). The chart maker assumes we know what these measures are, but I'm left none the wiser. You?
[/b][/quote]

im sorry, i figured that 18% versus 37% would be easy to understand. that is the good thing about ratios in that they are unitless and ideal for comparison purposes.

as usual, since it doesnt fit your point of view, you dont understand or dismiss it as frivolous data.

let me re-state some more frivolous data for you. its useless to compare other vehicles to the Prius for gas mileage improvements. you say its stupid to compare a Prius to a Camry, but its ok to compare a Prius to a corolla?

i dont understand why one unlike comparison is stupid while the other unlike comparison is ok.

you also state you are not any wiser after reviewing new data. that i can fully believe.

ok, now let me tell you what else i believe (you may stop reading now)

i believe you came in to this post with a lot of pre-conceived notions developed by reading stuff of questionable accuracy (i use CR's disclaimer for reference. they say that the data provided for all car reviews should not be taken as scientifically accurate)

i also believe you dont really care to objectively weigh other evidence and i state that what others have said here is no more accurate than what you have presented. there are no experts here. but we do have several real world experiences collectively presented here that you choose to not believe. instead you would rather believe someone who probably spent a grand total of a week with a Prius and then wrote a review on the car, and i'll bet 75% of what he said in his review was based on what he read in other reviews on the Prius.

 

<div class='quotetop'>QUOTE(DanP\";p=\"60912)</div>

I'm just now reading this thread so if this comment has been made before me but after this post of Dan's, I apologize.

I agree with Evan that some Prius MPG improvement techniques are not fully transferable to non full Hybrid vehicles. I have no data, just my experience. For example, all save by lifting off the accelerator early rather than keeping speed to the last moment before a reasonable stopping distance ( ie. no neck snapping stops). But:

• 
  
  It was icy last night, everyone was driving like they owned a Prius: slow starts, speed limit (or below) and plenty of room between cars. On one slight downhill section of the road traffic was 27 MPH, usually people go 35 in that 30 MPH section. Foot off the accelerator, ie coasting and charging but not regen, I was able to hold that 27 MPH for 1/2 mile. All other cars were burning gas, at more than idle to keep speed. The car dropped into stealth on its own in places I usually have to keep up with traffic so the computer doesn't make the steath decision.
  
  On the way home I used my new EV switch, starting at 8 blue, went 1.1 miles (slight uphill) at 30 MPH before it went to 2 pink and the engine started, just about the same place it would have to run anyway to go up the next hill. The engine running for the next 1/2 mile uphill was enough for it to make the final 1/4 mile (flat and down hill) on EV, selected by the computer, not me. Still 3 blue when I got home.
  
  Morning commute, as usual, involved no EV until I got very close to work. I forced it into EV for the 1/4 mile from the main road to the guard gate. That is one of the places the lack of computer determined EV gauled me. It is somewhat uphill , the car is warm, I'm at 8 blue or even green and *I* know I'm going to be stopping soon for 8+ hours and the engine will be running when I leave work to replace those amps I COULD be using.
  
  Yes, all that momentum originally comes from gas and the ICE but there are plenty of places where the ICE can handle the load and recharge those EV amps as well. I tested the EV switch after I installed it, 3 blue bars when I was done. My next trip was 2 days later, cold engine, round trip of 3 or 4 miles with a 2 hour stop and no EV at all. The battery was at 8 blue bars when I got home.
  
  I haven't yet had my engine run soley to charge the battery. In fact, on cold days, it has run at signals during the 1st 5 minutes to warm itself while charging the already at 9 green bars battery.

 

Sorry Bruce, your experience is irrelevant.

It's only an "anecdote" after all.

You see, we can only trust organized groups and/or "experts" to give us data on the cars some of us have driven for years. What we see and hear means very little. Our collective experiences are irrelevant.

:| :| :| :|

 

<div class='quotetop'>QUOTE(efusco\";p=\"61089)</div>

We'll see what actually materializes there. GM promised 60% fuel savings on the fleet of hybrid buses it sold to Seatle. The city has seen a 15% fuel savings.

 

Are you talking about that graph? Did I really "dismiss" it? You guys really need to check your emotional attachment to this car at the door. It seriously interferes with your reading. All I asked was what the hell the measure was supposed to be measuring. Do you know? I could make up a pretty graph, too, failing to indicate what the numbers indicated. Would that be of any value to you?

 

All that you say makes good sense. Those occasions when the motor turns itself off are obviously saving a lot of fuel, as all reviewers of the car have noted when explaining the superior city rating from EPA. This is clearly one advantage of Toyota's system over Honda's. And if your driving tends to involve a good deal of such stop-and-go driving, you're going to save more fuel than the guy whose driving is mostly commuting 30 miles on the freeway.

 

"On the way home I used my new EV switch,..."

Is this what I think it is? A way to manually force the HSD system to use all battery power?

Aside: I would be curious to know what the battery level was after Toyota's driver completed the EPA city test route (which runs about 30 minutes). After all, we have not arrived at the perpetual motion machine. The only time I have gotten the battery anywhere below 7 blue bars was when I was playing the CD while lacing on my leather steering wheel cover.

 

"You see, we can only trust organized groups and/or "experts" to give us data on the cars some of us have driven for years."

When dealing with Prius owners, yes, I'd much prefer independent data sources--not "experts," but persons who have no emotional attachment to the car. What I did not suspect, but now know all too well, is that Prius owners (or at least _some_ Prius owners) are quite passionate about their MPG ratings. This passion can easily warp their perception.

Here I thought I was going to share some friendly discussion about my new car with a group of other Prius owners; instead, I find that many the congregation think I'm a heathen Hummer in green clothing because I dared to question the one true God. I dared question the (absurd) claim that the Prius's HSD system nets a 90-100% improvement in gas mileage (a 25% god is not sufficient). I feel like I've just spit on the Holy Trinity in the middle of the Mass.

But I'll tell you what, how about if you just go your own way? You don't have anything substantive to add. If your last post is any indication, you just want to simper and cheer and sprinkle your pusilanimous happy faces about.

 

<div class='quotetop'>QUOTE(efusco\";p=\"61089)</div>

Well, Ed, at least you're consistent. You feel perfectly comfortable comparing the hybrid version to the V-6 version. Why not just compare it to an M-1 tank? You think that hybrid is goind to have a V-6 in it?

Speaking of V-6's, the new Accord hybrid is really something. And it would seem to offer a good chance at a straight comparison.

 

The only thing that GM can trump with their two mode hybrid system is theirselves.

 

<div class='quotetop'>QUOTE(DanP\";p=\"61244)</div>

This was directed to me:
<div class='quotetop'>QUOTE(DanP\";p=\"61244)</div>

So you go from wanting some "friendly discussion" to a personal insult?

 

I can tell by the looks of it that this discussion is heating up rather quickly. :mrgreen:

 

My response to you was perfectly justified by your inane remarks that were clearly insulting.

 

<div class='quotetop'>QUOTE(efusco\";p=\"61260)</div>

And you know this...how? You've suddenly taken to trusting Ford's press releases? Or have you always placed such trust in the Ford PR machine? The operative word in the above quotation is "touts." You clearly haven't learned Seatle's lesson about trusting the auto industry's hype. And don't ignore the fact that Ford's advertisers dwell on the "city" test, where a full hybrid driver can basically cheat the test by draining the car's batts for 30 minutes. (Let's see how they do on an average of 5 consecutive 30-min. tests with no driving between tests.)

Edmunds has been testing the Escape Hybrid for several hundred miles. Although they have been happy with the Escape's performance overall (even calling it "V-6 like"), they do note that the hybrid's 0-60 time is a second slower than the V-6 model. Net horsepower is down to 155 from 200: not quite up to the 4-cyl Camry's standard for raw, head-snapping power. And towing capacity is down to 1,000 lbs (from 3,500 lbs with the V-6).

Their fuel economy thus far has has been 25.5 mpg on their long-term test. By using a full hybrid drivetrain and also making some real trade-offs in power Ford has managed to improve fuel economy in the Escape by about 40%. Is it the same SUV? For some, yes--particularly if you don't tow anything and do not plan to drag race other SUV-owners for pink slips.

For my part, my eye is still on Honda's new Accord, where the engineers have not traded off any performance whatsoever (again, if we can believe Honda's hype!) and the _most_ powerful trim line is the hybrid (intriguing). And I'll happily eat my words about the overall benefit of hybrid technology when I see the hybrid V-6 Accord (which also uses a cylinder shut-down strategy, in addition to the electric motor) beat the the standard V-6 model by 30% or better.