GM says Two Mode Hybrid System Trumps Competition

<div class='quotetop'>QUOTE(DanP\";p=\"61234)</div>

Yes. There are threads elsewhere. Coastal Technologies makes a $45 plus shippng part that uses the Cruise Control stalk to do the same thing as the standard EV button in Japanse and EU cars. The software is in our cars but the switch isn't. You'll find instructions on how to wire in a separate 'do it yourself' switch (thanks to Dr. Evan Fusco) in the knowledge base.

There are limits on when it can be used and you can screw your MPG by using it at the wrong times. Best to learn where the car will go into EV on its own when fully warmed up but sometimes doesn't because it isn't warm enough and you haven't hit the magic 34 MPH after hitting the brakes but not stopping for ~ 10 seconds. One nice feature is that you don't have to be 'empty eggshell' light on the accelerator to gain speed and it doesn't kick out in slight hills. It DOES kick out above 34 MPH as opposed to 42 MPH for computer determined EV.

You won't if you drive mostly highway unless you are hitting long steep inclines, or don't have the opportunity to go into EV on city roads.

 

Unfortunately not! The V-6 Accord without the hybrid add on is a 240 HP 3.0 liter. The V6 with IMA in the hybrid has Variable Cylinder Management. VCM isn't available in the non hybrid. Thus, you still can't pull out any possible MPG gain based soley on the IMA. :-(

Accord specs
Horsepower] rpm (SAE net / with IMA)
240 @ 6250 / 255 @ 6000

Honda has the VCM V6 (slightly different bore/stroke) in the 2005 Odyssey EX with leather and the Touring version but there is no hybrid equivilent.

You CAN compare the V-6 VCM MPG directly in the Odyssey:
5-Speed Automatic (City/Highway)

without VCM: 19/25
models with VCM: 20/28

I don't know how much the weight difference hits the mileage nor how much weight the VCM adds vs other 'features'.
Curb Weight (lbs.)
LX: 4378
EX: 4475
Leather: 4537
Touring: 4634

 

Re: GM Hybrid Bus

<div class='quotetop'>QUOTE(DanP\";p=\"61221)</div>

That was an interesting article (I think it was in the Post-Intelligence) about the lack of expected gas savings in the GM hybrid buses. I thought the Metro engineer in charge of testing the busses sounded pretty honest about what went wrong.

Main points:

• The main reason the city went with these GM hybrid busses wasn't because of fuel savings -- it was emissions. The aging Italian busses Seattle uses puts out way too many fumes for the Seattle bus tunnel -- not good for the people waiting underground for a bus.
  
• However, the busses that use the bus tunnel (as opposed to stopping on the seattle streets aboveground) typically go much longer distances -- i.e., "express" lines that get out of the tunnel, get onto I-5, and then drive 15 or 20 minutes before getting out into their neighborhood.
  
  This means that the sort of stop-and-go driving where a hybrid bus would get its maximum fuel efficiency isn't the kind of route the GM busses are being used on.
  
  When the tunnel is engineered for the light rail system later this year, there's a good chance that the GM hybrids will be moved to street routes -- and thus see a considerable rise in MPG.
  
• Also, when Metro was doing the initial analysis of the GM hybrid busses, and they were getting great MPG ratings, the test busses used an engine which later had to be changed. The EPA (I think) had rulings that set the emission levels for new bus engines (?) at a lower level.
  
  Thus, Metro bought the GM hybrid busses with a "cleaner" engine -- but the MPG wasn't as good.
  
• The chief engineer also pointed out that these GM buses are much easier to maintain, and cheaper to run -- though he said that this was sort of a "shooting fish in a barrel" statistic. The Italian busses Metro has used are from the late 80s, break down frequently, and are almost impossible to get parts for.
  
  Almost anything that replaced them would look good in comparison.

 

<div class='quotetop'>QUOTE(DanP\";p=\"61298)</div>

What does the "standard V-6 model" get in the first place?

What type of driving you believe "overall" actually includes?

What is your source of baseline data to compare to?

Need I go on.... ?

The "assist" hybrid design doesn't provide much of a benefit in stop & slow traffic. Auto-Stop does re-engage unless you exceed 10 MPH. The VCM won't engage at all. And due to the passive charging system, the supply of electricity is very limited. So efficiency won't be good with this type of driving, which is pretty normal for many people. Highway-Only cruising isn't.

The system in Accord-Hybrid is specialized, not wide serving like that in Prius. It is dirtier too.

I suggest you get your ketchup ready.

 

<div class='quotetop'>QUOTE(bruceha_2000\";p=\"61325)</div>

Good point. I wish Toyota would integrate VCM into their system to yield a more "spirited" drive. It doesn't seem like it would be much of a problem. Part of me (less than 50%, however) wishes I had bought the new Accord instead. But I'm still happy with my Prius: the low emissions enable me to look down my nose at SUV drivers sitting several feet above me without hurting my neck.

BTW, thanks for the tip about the EV switch. I'll read up on it.

 

"Need I go on.... ?"

You may consider my standing answer to that question to be "no." Return to more useful pursuits--such as providing the world with yet another Prius photo album.

 

Why did you evade the question?

Again. . . How will you prove the "30% or better" ?

 

<div class='quotetop'>QUOTE(john1701a\";p=\"61536)</div>

It's not so much a matter of "evading" anything as it is of paying scant attention. But since you persist:

You seem to be laboring under a misapprehension: you seem to think I am seeking to prove a 30% improvement for hybrids (for the Accord in particular). If you like, I can tell you how someone with the means and the inclination might measure the effects of a hybrid system. It's not complicated.

It's simply a matter of holding other variables constant. One could do this by (a) taking two identical vehicles, (B) installing a hybrid system in one of them, making no other changes (e.g., one would use the same size gas engine in such a test), and © comparing the two vehicles' fuel economy (and performance, while you're at it).

From what I had heard about the new Accord hybrid, I had hoped that model might provide the needed test case (at least for Honda's system). As another participant (dispassionately) indicated, however, the Accord does not appear to present such an opportunity since it also relies on partially turning off certain cylinders when maintaining cruising speeds. I had overlooked that. So much for that idea.

As far as I'm concerned, the question is purely academic. It's not as if I'm going to trade in my Prius any time within the next 10 years or so. It's a sweet little car that gets 45 mpg and, in operation, does much less environmental harm than other cars. Since the question is purely academic, however, I'm also unwilling to swallow whatever wild claims auto makers and auto enthusiasts (fanatics) care to throw out there. People who believe in wild claims without evidence are the same people who believe in telekinesis, pyramid power, and George W. Bush's word. I'd rather not be numbered among any such persons.

 

<div class='quotetop'>QUOTE(bookrats\";p=\"61408)</div>

I didn't even see the whole article. I read a rewrite of the story in the San Diego Union. Thanks for the details.

 

<div class='quotetop'>QUOTE(DanP\";p=\"61543)</div>

What about the Escape Hybrid? They both use a 2.3l 4Cyl, altho there have been some engine management changes to the Hybrid version (which, really, shouldn't amount to much). And the CVT, which may disqualify the car....

Here are the EPA ratings for both FWD 2.3L versions:
Escape Hybrid 36/31
Escape 22/25

So there is a marked improvement with the Hybrid version.

 

<div class='quotetop'>QUOTE(DanP\";p=\"61543)</div>

What do you consider a big car?

Prius is bigger than Camry from just a few years ago and bigger than quite a few cars available now. In fact, the leg room is very close to the current Accord.

The "little" adjective should be dropped.

 

John,
I don't think he was using the term 'little' in a negative, or even size sense. Just a phrase. "sweet little car", "nice ride", etc.

 

<div class='quotetop'>QUOTE(DanP\";p=\"61524)</div>

The small 4 cyl Atkinson cycle ICE in the Prius is adequate for moving the car in the same way a VCM V6 running on 3 is adequate. The difference is that the electric motors in the Prius supply the the "need more NOW" HP, whereas the VCM engine just starts running all 6 cylinders.

I truely believe that the HID will add VERY little to the overall MPG gains of the Accord Hybrid. They could chuck in an electric motor to start the engine while using "engine off at idle" technology (a la GMC Silverado - NO propulsion from the hybrid system) without regen. There is no reason an ICE driven vehicle couldn't provide ALL the AMPs needed to start the vehicle over and over and over. Sure you might as well capture lost momentum as amps by running the electic motor backwards, but I really doubt you'll ever see an Accord hybrid ICE running for the sole purpose of charging the battery that runs the electic motor while driving in stop and go traffic.

When I first read Honda was going to put out a hybrid Accord, I thought "GREAT, larger than the Civic, popular among the American buyers". A choice for those that find the Civic too small.

I must say I am disappointed. Honda couldn't even get over the "rear seat backs don't fold" deal killer (at least for me).

I assumed it would be standard (to date then) design, smaller ICE, boosted when necessary with electric to yield roughly equivilent performance to the non hybrid version.

A 2004 Corolla LE automatic has a very slightly faster 0-60 than a 2004 Prius. Smaller car, less weight, lower MPG (EPA) by about 20 both city and highway.

I will be very interested to read a year from now what the general real world Accord hybrid mileage is, compared to a standard V6 Accord. If it is more than the difference between the VCM and non VCM Odysseys, we can then infer the MPG gain from the addition of the hybrid components.

I much prefer the "Electric first, ICE second" Toyota design. At first, when comparing the 2003 HCH and Prius, I figured it didn't matter all that much. But to be able to putter along in electric in the line at the dump, or fast food drive through, to move through the enclosed Blue Seal Feeds or lumberyard warehouses. Too sweet and oh so clean! Automatically drop into EV up to 42 MPH when conditions warrant. And now that I have my EV switch, I can move the car in the driveway or between stores at the mega box store mall (when I can't get what I need elsewhere) without it starting, the MOST polluting cycle. I can force EV in those places the computer would do it IF I had been able to stop for 10 seconds, but couldn't. I guess I'm just a big geek.

Nope, no mild hybrid for me. 0-60 in ~10 seconds is more than plenty, my Odyssey spec'ed at 13+ and I managed fine for 9.5 years and nearly 100K miles.

 

I can think of something else that should be dropped. You're dropped.

 

No need to continue the insults. They aren't helping your case.

 

What do you expect from an Internet Troll?

While he makes a valid point that some of the regulars on PriusChat are too passionate in their defense of the Prius from its critics, it would appear that he only came here to agitate and insult the majority of the posters.

:roll:

 

For someone with such a pathetically needy ego ('Look at me, John! I'm with you.'), it seems contradictory that you should also consider yourself "the majority of the posters." But perhaps you consider John to be the "majority" and yourself his valet. You are the only two people here who have insulted me; consequently, you are the only two people whom I have insulted.

That, however, is at an end: you're not worth the trouble.

 

I know what you mean. Although my last car was a V-6 Camry, I can't say I really miss the extra "oomph" very often--not for the kind of driving I do. And the high mpg and small ecological footprint are sources of satisfaction in themselves. A friend of mine bought a Civic hybrid about a month before I did. His best tank has been 41 mpg. I told him I've gotten 45 mpg for the first 3 weeks I'd owned the car--mostly by just driving the speed limit (for a change) and stopping and starting gradually. I'm pretty sure I saw envy in his eyes. I suppose it's wrong to enjoy another's envy, but I did.

BTW, I assume that when you say 42 mph is the top speed for EV mode you're talking about relatively flat ground, for one time on the freeway to San Diego I was travelling down about a 3 or 4 percent grade doing 70, with the Prius in EV mode most of the way down the hill (about a mile). That surprised me.

 

Yes, I agree, there is a marked improvement in the Escape hybrid, compared to the 4 cyl ice: about 24% for the highway test and about 63% for the city test. I think it's reasonable, however, to be rather suspicious of the city test. After all, the average speed on that test is about 20 mph, so a full hybrid can run on EV much--even most--of the time; but the test is only 30 minutes, and I'd be interested in learning the condition of the battery's charge after those 30 minutes (maybe it's full; maybe it's depleted: I just don't know). The improvement on the city test is still really impressive--but perhaps not _quite_ as impressive as the test numbers indicate.

 

Well, the Escape has no way for the driver to see the battery's SOC, which probably isn't a bad thing... you can't really do anything about it either way after all. Even if you disregard the city results, which is a bad idea, you still get a 24% improvement.

The bad bit about disregarding the city results is that the car is *designed* to work in EV mode much of the time when it's in stop and go traffic. My Prius will cruise thru a few towns in EV mode entirely on my way home, and while it's cool and all, it's how the car was designed to work.

BTW -- ignore the twits. They can't handle any constructive discussion of cars and technology. They're like OS/2 users, circa 1995.