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2011 Chevy Volt
But Volt's true nature may actually be an improvement, plus early reviews are complementary

In the week when auto editors turned in their first reviews of test drives of General Motors' upcoming 2011 Chevy Volt, there's been a bizarre twist that's largely overshadowed these initial impressions.

In a wild twist, Larry Nitz, GM's executive director of electric and hybrid powertrain engineering, has revealed that the gasoline engine actually will drive the Volt mechanically.

Previously, GM had maintained that the Volt was a battery electric vehicle (BEV).  When the battery's 40-mile range (since revised to "25 to 50 miles") was nearing exhaustion, a turbocharged 1.0-liter 3-cylinder gasoline engine kicked in, supply electrical current directly to the batteries and motor to provide more than 200 extra miles in range.

That platform was known as "E-Flex".  But unbeknownst to anyone, GM was pulling a bait and switch.

Today, Mr. Nitz revealed that 
actual powertrain.  The Volt, it turns out, is not a BEV like the 2011 Nissan Leaf.  It is actually a plug-in hybrid electric vehicle (PHEV) like the 2012 Ford Focus or 2012 Toyota Prius EV.

The internal combustion engine (ICE) -- now a 1.4L 84 hp 4-cylinder design -- and the 149 hp permanent-magnet AC electric motor both feed into a planetary gear set and three electronically controlled, hydraulically activated multi-plate clutches.  The resulting automatic transmission is marvel of electro-mechanical engineering offering a blend of efficiency and power.  The entire powertrain is bolted together to minimize noise, vibration, and harshness (NVH) and reduce space usage.

Arguably this advanced transmission is much better for customers than what GM initially 
said it was offering.  As Ford Motor Company pointed out in our recent interview with their head of electrification, BEVs suffer from poor performance in cold or hot weather, as the battery's performance deteriorates sharply. 

So why the bizarre farce on GM's part in claiming its BEV was really a PHEV, when the actual design would be more beneficial to the majority of customers?  Mr. Nitz claims that GM had to deceive the public in order to secure its patents on its unique transmission.  Now with the patents in hand, he was free to go public with the new powertrain platform, dubbed "Voltec", he says.

Turning to what GM had intended to be the focus this week, 
MotorTrend and The Detroit News have taken their first drives in the upcoming PHEV and are quite enthusiastic.

The Detroit News writes:

After I drove more than 32 miles on electric power only — in a very un-eco-friendly manner — the Volt’s little engine began powering the car. This was the moment I had been waiting for: It’s one thing to power a car with batteries, but it’s revolutionary to have a gas engine supply the power to electric motors.
The succession of power is more seamless than a presidential election. The engine is quiet and keeps humming along. There’s never a glitch, a pause or a moment when the engine noticeably kicks on or off. For the most part, once the initial battery charge is drained, the engine produces the electric power to drive the motor. 
...

Most of all, there's nothing to adjust to in the Volt. My 75-mile trip used a total of 0.9 gallons of gasoline. But I would have been happy to drive farther. 

And MotorTrend opines:

The Volt is no sports car, but it blows Toyota's plug-in Prius away (9.8 seconds to 60 mph), and runs neck and neck with a 2.4-liter Malibu in acceleration and handling tests. Figure-eight performance is virtually identical at 28.4 seconds and 0.59 g, and the Volt's 119-foot stops from 60 mph are just 3 feet longer-impressive, given its 226-pound weight disadvantage and low-rolling-resistance tires. (The Prius weighs 376 pounds less than the Volt, yet it just matches its 0.78g lateral grip, trails both Chevys by 0.4 second on the figure eight, and needs 131 feet to stop from 60 mph.)

Based on these reports it appears that GM's "surprise" of the ICE hooking up directly to the transmission to drive the wheels seems indeed to be a good one.  On the other hand, many will likely dwell on the fact that GM pulled a bait-and-switch on the customer.  

After all, some customers really want an honest-to-goodness BEV and may now being a bit bummed that they instead ordered what essentially amounts to a souped up plug-in hybrid.  Others have been vocal critics of the vehicle (and GM in general) and will likely jump on GM's deception as a platform to attack the vehicle (and GM in general).

Perhaps GM was right -- they had to mislead the public to protect their intellectual property.  But the move was certainly a very bad decision in terms of public relations.  GM can only hope that the public settles down and comes to realize the bottom line -- that it's offering them a superior package than what it initially promised to deliver.



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MPG is all that matters
By mattclary on 10/11/2010 2:13:33 PM , Rating: 5
end of message...




RE: MPG is all that matters
By lennylim on 10/11/2010 2:21:41 PM , Rating: 4
Don't forget the price. I think it matters a lot too.


RE: MPG is all that matters
By Mojo the Monkey on 10/11/2010 2:47:11 PM , Rating: 4
Seriously. Without a new drivetrain tech in place, which might have satiated some early-adopter-technophiles, this is a WAY overpriced hybrid with numbers that are far below expectations for that kind of price premium. Fail.


RE: MPG is all that matters
By Schadenfroh on 10/11/2010 5:57:58 PM , Rating: 5
Thanks to our government, you get to help subsidize that price.


RE: MPG is all that matters
By chick0n on 10/11/2010 10:55:24 PM , Rating: 2
Its called Government Motors for a reason.

Everything fails.


By therealnickdanger on 10/12/2010 9:08:00 AM , Rating: 5
*ahem*

Too big to fail.


RE: MPG is all that matters
By stirfry213 on 10/12/2010 1:25:35 PM , Rating: 2
Even subsidized, this product is WAY too expensive for what it is. There is nothing revolutionary about this product. I'm convinced this will be a failure, I just hope it fails before significant amounts of our tax payer dollars are wasted on this POS.

*wave hand*
This is not the car you've been looking for...


RE: MPG is all that matters
By sinful on 10/12/2010 7:59:37 PM , Rating: 2
You don't understand, the benefits will TRICKLE DOWN to you!


RE: MPG is all that matters
By spread on 10/13/2010 3:32:12 AM , Rating: 3
Golden shower economic theory.


RE: MPG is all that matters
By Mojo the Monkey on 10/13/2010 1:46:14 PM , Rating: 2
This is priceless.


RE: MPG is all that matters
By mattclary on 10/11/2010 3:55:25 PM , Rating: 2
Agreed 100%.


RE: MPG is all that matters
By invidious on 10/11/2010 5:40:50 PM , Rating: 2
Total cost of ownership is all that matters if you are thinking with your wallet. After looking at the total cost of ownership of electric cars vs normal cars I was not impressed.

FYI I decided to buy a 2011 mustang convertible because how much fun you have with your money is more important than how much you spent.


RE: MPG is all that matters
By solarrocker on 10/11/2010 2:41:36 PM , Rating: 2
size would matter to me also, mean would like to transport a little more then a hamster if possible.


RE: MPG is all that matters
By RivuxGamma on 10/13/2010 2:56:54 PM , Rating: 2
Eff that. I don't want Richard Gere as my passenger.


RE: MPG is all that matters
By Fenixgoon on 10/11/2010 2:44:19 PM , Rating: 2
I disagree - the reason why the volt was supposed to be so impressive (and warrant its price tag) was that it was a series hybrid, unlike any other vehicle to date.

Not that I'm in the market for the Volt, or any hybrid, but I'm either disappointed or angered by this announcement, not sure which.


RE: MPG is all that matters
By nafhan on 10/11/2010 2:54:46 PM , Rating: 2
And the reason series hybrid is supposed to be impressive was because it would supposedly use less gas... If they're meeting the advertised performance figures (which have never been completely clear to me) and not changing the price, it shouldn't matter what type of powertrain they use.
I will say that this is kind of weird, though.


RE: MPG is all that matters
By Spivonious on 10/11/2010 2:57:14 PM , Rating: 1
Exactly. The Volt has become an overpriced Prius. Why won't we just let GM go out of business? They are incapable of producing anything revolutionary.


RE: MPG is all that matters
By MozeeToby on 10/11/2010 5:06:46 PM , Rating: 5
Ok, reading through the source article to make sense of what has all changed and it's not as clear-cut (at least to me it isn't) as the DT writers make it out to be. I'll try to make this clearer that the source did:

The volt has two electric motors, a drive motor which is the primary and a smaller secondary motor that kicks in at high speeds but also does double duty as the generator. If there's juice in the battery, the two motors work together to achieve high speeds. Where it gets interesting is if there isn't juice in the battery.

At low speeds, if the battery is depleted, the small motor disengages from the drive train and connects up with the gas engine to recharge the battery. Everything up through this point the Volt is working as advertized. At high speeds, however, the primary drive motor doesn't have the horsepower to power the car by itself.

At this point, the secondary motor/generator engages into the main drive train and begins to push the car as well. However it is continuing to function as a generator at this time, the energy that is actually turning the motor is coming directly, mechanically from the gas motor. At this point, the Volt is (rather confusingly) acting as both a serial and a parallel hybrid.

Drive Train <------ Primary Drive Motor
`````^```````````````^
`````|````````````````|
Secondary Motor <-----> Battery
`````^``````````````````````
`````|``````````````````````
Gas Engine

And yes, the arrows are important and accurate in the diagram, the secondary motor both charges the battery and acts as a mechanical pass through to drive train. This allows them to get away with less total weight and cost in electric motors (since the secondary motor is doing double duty as a generator). It also means that this does not break the drop in replacement idea the generator. Anything that can either A) charge the battery at a high enough rate that both motors can be run simultaneously or B) turn the secondary motor at the correct rate can be dropped in as a replacement.


RE: MPG is all that matters
By Alexvrb on 10/11/2010 8:10:06 PM , Rating: 2
So basically it has the best of both worlds? True serial operation when the battery is juiced up, and improved parallel operation when the battery is down but you still need to haul butt? Nice!

Thanks for the explanation and especially for that diagram, Mozee. MUCH better than the WTFBBQ article above.


RE: MPG is all that matters
By priusone on 10/11/2010 8:13:24 PM , Rating: 2
Great job at explaining how the system works. I had wondered why the ICE wouldn't help power the rig while charging the batteries. Going from gas -> generator -> electric motor -> powertrain and not including the ICE into the power train sounded strange.

It would be neat be have an option that would prevent the ICE, while charging the batteries, from contributing to the powertrain just to spite those who are crying about GM making a smart move. Personally, I thought people salivated at the thought of power draining extra HP.


RE: MPG is all that matters
By ilkhan on 10/11/10, Rating: 0
RE: MPG is all that matters
By priusone on 10/12/2010 12:07:26 AM , Rating: 2
What part of the article or comments make you think that it must use the ICE? Don't go over the 30+ mile limit and all it should use is the electric motor.

People paid good money for Pruis's and without a major retrofit, could they travel 30+ miles without the engine kicking on? Yeah, hydrogen fuel cells will be great when we finally have access to them, and having more solar panels and more energy dense batteries will be awesome, but do we complain about a major automaker embracing electric vehicles or do we see the glass has half full?

As was stated in my other post, kudos to GM for making a vehicle that coulf travel 30+ miles without gasoline, and for way under $100,000


RE: MPG is all that matters
By topkill on 10/12/2010 2:31:13 PM , Rating: 3
You're confusing 30 miles with 30mph. What GM is saying is that when you get up to highway speeds the ICE kicks in to help turn the wheels because it is more efficient for high speed driving.

This has nothing to do with the all electric range.


RE: MPG is all that matters
By Solandri on 10/12/2010 12:29:13 AM , Rating: 3
quote:
Even with this explanation I'm pissed. Part of the reason people loved the series hybrid idea is that the battery provides 100% of the actual propulsion. At which point you can replace the ICE with a fuel cell, or a bigger battery, or solar, or whatever else you want without changing the vehicle's performance.

The Volt can still do that. All that's changed is that instead of the electric motors driving the wheels directly, there's a drivetrain between them and the wheels. A secondary motor hooked up to the ICE is also connected to this drivetrain.

If you think about it, it makes a *lot* more sense to do it this way than the pure electric model people thought it was going to be. In the pure electric model, the electric motor drove the wheels - always. When the battery ran out of juice, the ICE would drive a generator which converted the mechanical energy into electricity, which would be sent to the electric motors, which would turn it right back into mechanical energy. You're probably looking at 80%-90% efficiency there tops, probably more around 75%.

The way GM is doing it, while the battery has juice, the car is driven purely by the electric motor. You lose a tiny bit of energy in the drivetrain, but it should be minor (they're typically 98%-99% efficient at transferring power). If the battery runs out of juice, the ICE gets a direct mechanical linkage to the wheels thus eliminating any conversion losses.

Bottom line is, the primary goal here is energy efficiency. The direct mechanical linkage between the ICE and drive wheels is more efficient than having to convert mechanical energy, to electric, back to mechanical energy. The only people who should be upset about this are people whose primary goal is the elimination of ICEs, even if it causes lower energy efficiency. Those people are not environmentalists, they're social engineers trying to make the world conform to their flawed (less efficienct) view of how the world should work.


RE: MPG is all that matters
By DominionSeraph on 10/12/2010 3:05:55 AM , Rating: 2
Does the system balance torque so the ICE operates at wide-open throttle to both charge the battery and aid the driveline? Because if it doesn't, while the mechanical linkage may be efficient, you're losing efficiency in the ICE.


RE: MPG is all that matters
By Solandri on 10/12/2010 6:04:05 AM , Rating: 2
Yes, that occurred to me after I posted. But any decrease in ICE efficiency due to not operating at ideal RPM has to be less than the efficiency losses in converting the power to electric and back to mechanical energy. If that weren't the case, auto makers would be redesigning every ICE car in production to replace the mechanical transmission with an electric generator -> electric motor setup.

Since that isn't happening, it's safe to conclude the a mechanical linkage with sub-optimal ICE RPM is more efficient than an electrical linkage with optimal ICE RPM. Automakers have been trying for decades to obtain the holy grail of a continuously variable transmission. If it were possible to do that using a generator and electric motor, they'd have done it already. They haven't done it, ergo the efficiency losses in a generator -> electric motor combo exceeds the efficiency losses from running the ICE at sub-optimal RPM.


RE: MPG is all that matters
By ilkhan on 10/12/2010 4:01:22 PM , Rating: 2
What I read is that at highway speeds, the ICE uses some of its output to directly power the wheels, the generator doesn't put out enough juice to power the wheels at freeway speeds on its own without the battery providing additional juice. Thus the problem. It may be better for simplicity but it kills the concept of series hybrid.
Also as mentioned below, mechanical simplicity takes a huge hit this way.


RE: MPG is all that matters
By MozeeToby on 10/12/2010 5:04:05 PM , Rating: 2
Well, close. The generator probably does put out enough electricity to power both electric motors directly, the problem is that the second motor (the motor that is necessary to reach freeway speeds) is busy functioning as the generator. It simply isn't available to provide power to the wheels because it is busy charging the battery. So, since this electric motor already has a connection to the drive shaft (to help the primary at freeway speeds) and to the ICE (to charge the battery) they just hook up both connections at once.

So, if you had, for example, a hydrogen fuel cell that could supply enough electricity to charge the battery faster than both motors deplete it at highway speeds, you could drop that in as a replacement for the ICE. You just remove the mechanical connection to the secondary motor, make a software change to the gearing system, and everything else stays the same. You could even do the same thing with an ICE, but you'd have to bring along your own generator to make it work.

Honestly, except for a pretty big leap in complexity (and therefor maintenance costs) it seems to be a better design. Personally, I would have preferred a single drive motor and a direct serial connection, but this is, in a different way, a very brilliant design.


RE: MPG is all that matters
By MadJak on 10/12/2010 3:50:14 AM , Rating: 2
you will probably find that the ICE can still run at optimal power bands. There will be a planetary gear system that will either feed the power of the ICE to the Secondary electric engine for 100% power store to batteries, or bipass the electric engine to drive the wheels. Kinda like the toyota CVT. This is probably where the patent will be.

So the engine can run at a set RPM and sit in it's efficiency band, and have part of its power split to the wheels and/or part to generate power to be stored into the batteries. The ratio will depend on how much power you need at specific speeds and whether or not that can be supplied by the electric engines(s) or needs the ICE to boost.


By Thats Mr Gopher to you on 10/12/2010 6:11:16 AM , Rating: 4
Jason Mick FAIL
MozeeToby WIN


RE: MPG is all that matters
By espaghetti on 10/12/2010 12:44:16 PM , Rating: 2
Does this mean that I no longer need to plug this car in to charge the batteries?

I don't see that in your otherwise incredible diagram.


RE: MPG is all that matters
By MozeeToby on 10/12/2010 12:51:38 PM , Rating: 2
You never had to, even with the old way that it worked. If you want your 25-50 miles of all electric operation you'd want to plug it in whenever possible and charge the battery. If you don't plug it in, the ICE kicks in to provide both energy for the battery and, in the more recently released design, mechanical power for the drive train. As always, you can still drive the Volt everyday without plugging it in, you'll just use more gas that way.


RE: MPG is all that matters
By espaghetti on 10/14/2010 2:07:18 PM , Rating: 2
Thank you


RE: MPG is all that matters
By Marlonsm on 10/11/2010 3:03:41 PM , Rating: 5
In the article, in a 75 miles drive, 32 of which being electric the car used 0.9 gallons, it means 47.8MPG after the engine started.
Not a bad consumption, but to be honest, I expected more.
Maybe when battery tech advances and cars like the volt won't need to carry all that extra weight.


RE: MPG is all that matters
By MonkeyPaw on 10/11/2010 8:45:50 PM , Rating: 2
The guy did say he drove it pretty hard. 47mpg may not be so bad if he was dogging the crap out of it. If he was babying it, then yeah, that's not fantastic.

What I would like to know is the range of the vehicle. 230-250 miles on a tank is pretty bad if you do long trips a lot.


RE: MPG is all that matters
By Reclaimer77 on 10/11/10, Rating: -1
RE: MPG is all that matters
By MozeeToby on 10/11/2010 4:09:45 PM , Rating: 3
Maintenance matters quite a bit too. An all electric drive train is relatively indestructible and having the gas motor only running at the perfect point of its power curve also improves reliability, putting that mechanical power directly to the drive train adds all kinds of complexity and presumably adds full transmission into the mix as well. It takes this from a design that is far simpler than a traditional auto to a design that is far more complex than a traditional auto.

Also, secrecy needed to protect patents? That isn't how the patent system works. If you publish, you're protected. If you don't publish and the competition comes up with the same idea (either via convergent design or a leak) you're SOL. His explanation makes no sense (unless he really thinks that the design is so groundbreaking that it was worth the risk just to get an extra 6 months of coverage at the end of the patent's life).


RE: MPG is all that matters
By Gungel on 10/11/2010 4:20:55 PM , Rating: 2
So why should I route the power from the engine to generator to the battery tho the electric motor to a transmission and than to the wheel when I can just go strait from the engine to the transmission to the wheel without adding all that loss of efficiency. I think it's actually great news for the Volt that we combine range extender and hybrid.


RE: MPG is all that matters
By dubldwn on 10/11/10, Rating: 0
RE: MPG is all that matters
By tastyratz on 10/11/10, Rating: 0
RE: MPG is all that matters
By MozeeToby on 10/11/2010 4:40:58 PM , Rating: 2
A) With a serial hybrid there is little to no need for a mechanical transmission of any kind. Depending on the electric motors used they can power the wheels directly, and a properly tuned engine can directly run the generator.

B) If the gas engine is only being used to charge the battery, it can be highly tuned to a very narrow power band. That gets more power out of a smaller engine, something that is only possible because the engine can always be running at the same RPMs. Being able to tune the engine to a narrow power band allows you to greatly increase the efficiency, enough to overcome losses in the generator and batteries.

C) A drive train that is taking power from two different sources (an electric motor and a gas engine) will be, by definition, more complex than a drive train taking power from only one. That makes maintenance more difficult and failures more likely.


RE: MPG is all that matters
By 91TTZ on 10/11/10, Rating: 0
RE: MPG is all that matters
By foolsgambit11 on 10/11/2010 9:45:57 PM , Rating: 2
Because, amazingly, it is possible to have less total energy transmission losses by going from generator to alternator to batteries to electric motor to simple electric transmission to wheels than having an ICE-to-transmission-to-wheels setup. It's all about how much more efficient a generator running at peak efficiency is compared to a engine tuned for direct propulsion (which needs a wider, but inherently less efficient, power band), coupled with the fact that the losses in each step along the electrical trail are smaller than the losses along the mechanical one.

To be honest, most of my (albeit lay) knowledge of serial hybrid systems like this comes from reading up on sailboat propulsion systems, which do have different torque/horsepower requirements (and user priorities as far as fuel usage and engine running time), so losses in a car's transmission for an electric motor may be greater, and the trade-offs in other ways may make less sense. But serial hybrids have been in use on some high-end sailboats for a few years now, I think.


RE: MPG is all that matters
By bug77 on 10/11/2010 5:41:26 PM , Rating: 3
quote:
Maintenance matters quite a bit too. An all electric drive train is relatively indestructible...


The drive train may be relatively indestructible (the Titanic was supposedly unsinkable), but the battery is not. That's going to have a huge impact on both the maintenance cost and resell value.

There's only one thing sure about EVs: they're not ready yet.


Confused
By dsx724 on 10/11/2010 2:16:51 PM , Rating: 1
I'm still a little confused. Wasn't that the original design???

Motor --> Transmission <--> AC Motor <--> Inverter <--> Battery
                                |
                                |
                              V
                        Wheels




RE: Confused
By Brandon Hill (blog) on 10/11/2010 2:22:16 PM , Rating: 5
Originally, the gas motor was supposed to supply electric current to the drive motor (once the 40-mile range was exhausted) to keep the vehicle moving.

Now, it's shown that the gasoline engine can actually couple with an automatic transmission (never previously discussed) to directly power the wheels instead of simply providing juice to power the electric motor.


RE: Confused
By SublimeSimplicity on 10/11/10, Rating: 0
RE: Confused
By foolsgambit11 on 10/11/2010 3:41:19 PM , Rating: 3
Well, in the sense that a high-level diagram of the two (assuming you meant the upcoming plug-in Prius) would look the same, you are correct. But the engineering and implementation of each of the parts in that diagram is different.

The part that bothers me is their explanation. I understand that extreme temperatures can cause problems for batteries, but couldn't they route power from the generator directly to the motor as well as the batteries, thereby allowing the drive train to bypass the batteries when dealing with very hot or very cold temperatures? It would simplify the mechanics of the transmission (and probably ultimately increase its efficiency), while making the electrical system only nominally more complicated. The IC generator would run more in extreme climates, but the engine will do that with the newly revealed design as well.

Odds are, the real explanation is that they couldn't get enough HP out of the electric motor alone (while hitting their price point), so they added the engine in to boost performance when needed. It's certainly cheaper to get 233 HP out of a 149 HP electric motor and a 84 HP IC engine than having a 233 HP electric motor and a 233 HP IC engine (though the engine could probably be a bit smaller since full HP isn't needed all the time, and charging the batteries the rest of the time would provide the power for full HP output when needed).


RE: Confused
By MozeeToby on 10/11/2010 5:12:42 PM , Rating: 2
It isn't actually, read the source article or my post above, it's all a bit more complicated that the DT writers make it out to be.


RE: Confused
By Reclaimer77 on 10/11/2010 8:27:21 PM , Rating: 3
quote:
Now, it's shown that the gasoline engine can actually couple with an automatic transmission (never previously discussed) to directly power the wheels instead of simply providing juice to power the electric motor.


Yes, the gas engine that requires premium. Still not understanding that decision.

The Volt's a disaster. It was marketed as a revolution, now it's just a less efficient plain old hybrid, a money pit at that.


RE: Confused
By YashBudini on 10/12/2010 10:35:46 AM , Rating: 2
You're right, I agree 100%


RE: Confused
By Reclaimer77 on 10/12/2010 11:35:21 AM , Rating: 2
quote:
You're right, I agree 100%


HUH? Yash you feeling ok today? :)


RE: Confused
By JasonMick (blog) on 10/11/2010 2:25:41 PM , Rating: 2
No in the original design it was:

Motor --> AC Motor <--> Inverter <--> Battery
............|
............|
............V
.......Transmission
............|
............|
............V
.........Wheels

Everything fed through the AC motor, be it current generated by the gas engine or juice from the battery.

With the new design, however, your diagram is accurate, as the motor can feed DIRECTLY to the transmission.

This will probably be a good thing for performance, but some will be likely turned off by the fact that GM misrepresented the car as a BEV with a range extender, rather than a plug-in hybrid (what it truly is).


RE: Confused
By Ammohunt on 10/11/2010 3:07:10 PM , Rating: 3
BEV,PHEV, TGEV doesn't matter is still over priced and over hyped. Pass....


RE: Confused
By thorr2 on 10/12/2010 4:51:23 PM , Rating: 2
So was the first automobile. Horses were much better. Time, interest in the product, optimization and funding made it better in the long run.


RE: Confused
By dsx724 on 10/11/2010 3:38:34 PM , Rating: 2
With either setups, the long term reliability sucks since your using a single vector for three high torque/high power devices. One component failure will shred that transmission along with whatever else is attached to it.
GM is going to need divine intervention to save their collective asses.


RE: Confused
By SandmanWN on 10/12/2010 12:51:40 AM , Rating: 2
Check out MozeeToby's post for the correct layout. Even when the Gas motor is powering the (secondary) drive motor directly to the transmission it is still charging the battery and performing the job of both serial and parallel at the same time. You sir are confused and have thrown egg on your own face yet again.


RE: Confused
By ianweck on 10/12/2010 11:32:31 AM , Rating: 3
This.

I have to laugh, so many people just waiting to bash GM or the government, or both. Bash first and often, maybe ask questions later.


RE: Confused
By Reclaimer77 on 10/12/2010 11:48:33 AM , Rating: 2
quote:
I have to laugh, so many people just waiting to bash GM or the government, or both.


I have to laugh that you don't think GM and the Government have given people PLENTY of reason to "bash".


RE: Confused
By ianweck on 10/12/2010 12:06:22 PM , Rating: 2
If you have a reason, then bash away. My point is in this case, there's no reason.


RE: Confused
By Reclaimer77 on 10/12/2010 7:09:14 PM , Rating: 2
There's always a reason to bash. Lotta anger out there and people need an outlet.

But GM and the Government? Never before were there such a combination of easy targets.


Either way
By Sazabi19 on 10/11/2010 2:23:28 PM , Rating: 5
there was going to be a ICE running at one point or another once the battery was drained... so is it really that big of a deal? Sure it wasn't nice to decieve us but it really isn't that much different. Am i wrong in my thinking here?




RE: Either way
By chromal on 10/11/2010 2:50:02 PM , Rating: 2
Well, the original design GM was touting was that the engine would serve the role of an APU (Auxillary Power Unit) as opposed to direct locomotive force. The idea there was that they would have more flexibility, e.g.: 3-cyl turbo APU? fuel cell APU? turbine APU? extra battery alternative to APU? No problem, they all work interchangeably. This is an old idea applied to automotive technology, which would have been revolutionary.

Here, with what GM's *actually* going to be doing, we're looking at a heavy and expensive Prius rehash with Detroit-designed/built reliability/efficiency/resale value... which I don't perceive as very reassuring. On the bright side, it will make the MPG numbers a more meaningful comparison with other hybrids, I guess, but we're no closer to some of the exciting possibilities GM that strip-teased the world with.


RE: Either way
By dubldwn on 10/11/2010 3:39:18 PM , Rating: 1
quote:
Am i wrong in my thinking here?

Yes. This is a big deal. The power train GM described was a true EV that we could envision improving over time with smaller, more powerful batteries and lighter, more efficient engines to generate electricity (or different engines all together, as the poster above alluded to, operating at maximum efficiency). This is now just a Prius of Fusion with a huge (and expensive) battery.


RE: Either way
By foolsgambit11 on 10/11/2010 3:58:40 PM , Rating: 4
The maximum efficiency part is the key to the difference. An electric motor runs near maximum efficiency at all points along its power curve, so it is the most efficient propulsion mechanism available (practically speaking). An ICE only runs at peak efficiency at one point along its power curve; all other output levels are, essentially, wasting gas. So tune an ICE for high efficiency at one point on its curve, and send that power to a storage medium (batteries), so it can be drawn on by the electric motor, and you have the best efficiency possible for an automobile with current tech.

(A note on batteries - they generally are less efficient when drained at higher speeds. They aren't like a reservoir in that sense - the faster you drain the power out, the less total power you can get from the battery. This complicates the total system efficiency calculations, but ultimately, serial hybrids should still come out ahead. Now back on subject....)

With the new layout, the engine is probably de-tuned to have a lower peak efficiency but greater efficiency over a range so it can effectively power the transmission. Plus, the transmission has become more complicated, increasing power losses there. From a reaching-for-perfection standpoint, these are disappointments, but I can understand there was likely some good logic to it. By coupling the ICE to the transmission, you reduce the total HP of all components necessary for a given level of performance, thereby reducing manufacturing costs, at the expense of lower fuel economy. It's all a trade-off.


RE: Either way
By clovell on 10/11/2010 5:05:58 PM , Rating: 2
Big difference in durability & maintenance costs & moving parts. This is the entire crux of Serial vs. Parallel hybrid automotive design.


RE: Either way
By Reclaimer77 on 10/11/2010 8:38:35 PM , Rating: 2
quote:
Am i wrong in my thinking here?


YES


turbo'd 3 cylinder??
By cruisin3style on 10/11/2010 2:33:43 PM , Rating: 2
I'm pretty sure the volt having a 4 cylinder engine in it isn't news.

Actually, to me, the news on the motor front is that there was a 3 cylinder turbocharged motor in the works previously...or recently enough to merit saying GM using a 4 cylinder instead is news.




RE: turbo'd 3 cylinder??
By chromal on 10/11/2010 2:51:15 PM , Rating: 2
I assume dropping the turbo'd 3-cyl is about permitting the use of regular unleaded 87-octane fuel over the more-expensive 91-94 octane a higher-compression turbocharged engine would require.


RE: turbo'd 3 cylinder??
By BWAnaheim on 10/11/2010 3:24:25 PM , Rating: 2
A while back I recall reading that the 3-cylinder was not as smooth as originally anticipated and could not supply enough power at a low enough RPM to give the right overall experience. It makes sense, though, to go with a 4-cylinder engine for a balance of 87-octane, power, and availability (now being produced in U.S.). Given that the gasoline motor supposedly kicks in for drive assist above 70 mph, going with the larger gasoline motor is even more sensible.


Is it me or...?
By Goty on 10/11/2010 2:39:49 PM , Rating: 2
Did I just misunderstand the article, or is that Detroit News excerpt completely missing how this powertrain functions?




RE: Is it me or...?
By walk2k on 10/11/2010 3:20:03 PM , Rating: 2
The second thing....


RE: Is it me or...?
By Dorkyman on 10/11/2010 7:28:19 PM , Rating: 2
I dunno, something sounds really hinky to me.

It might turn out, if the article is true, that GM has pulled off a clever fake-out with its Japanese rivals. Or it could turn out that GM is just full of crap and the car is a loser.

I COULD make some comment about how it figures that ObamaMotors would smile and lie while looking right at you with a straight face. You know, Chicago politics here, also. But that would be unfair to Obama. Everyone knows that if this car bombs it was because of Bush.


The Volt is a Range Extened BEV
By KingofL337 on 10/11/2010 3:36:56 PM , Rating: 2
The Volt NEVER couples the engine to the wheels while in charge depletion mode. When running on batteries it is as true of an EV as the Leaf or the Tesla.

The Volt will only connect the gas engine to the drive-train over 70MPH.

At 70MPH the generator helps the AC motor propel the car to 101MPH when the car is in BEV mode. When the battery is being sustained the generator cannot help the AC motor as it's generating power. The gas engine then uses mechanical connection to the generator to assist the AC motor. At that time generator motor is both charging the battery and propelling the car. The car cannot move without the AC motor.




By tallguywithglasseson on 10/11/2010 3:51:51 PM , Rating: 2
Hm, that makes sense. Too bad I already posted (below) a whole rant. Teach me to read this blog (and its tendency to overstate things) and not research the entire source article.

Electric motors are generally great at acceleration (and torque) but not at hitting higher top speeds. That [having the ICE assist in driving the wheels only at higher speeds] might actually be a pretty smart design.

I still think they could have clued the public in a bit earlier, it's their own fault they're getting bad press.


By foolsgambit11 on 10/11/2010 9:23:38 PM , Rating: 2
Your first paragraph seems a little disingenuous, since it seems from the rest of your post that the definition of 'charge depletion mode' is 'when the engine isn't on' (making it basically a tautology), not 'when there's juice in the batteries to be used'. For instance, you could have just unplugged the Volt, driven out of your driveway and onto the highway, and you'll be using the ICE to propel the vehicle directly.

However, it is good information to know that the gas engine only connects to the drive train directly for acceleration at high speeds.


drivetrain shrink
By RU482 on 10/11/2010 2:31:36 PM , Rating: 2
So this sounds more like the hybrid system in the Tahoe/Escalade, just shrunk down in scale and optimized for a wider range full electric mode.

It's funny how there is almost this sentiment of anger on the various message boards about how GM duped us.




RE: drivetrain shrink
By chromal on 10/11/2010 2:52:30 PM , Rating: 1
quote:
It's funny how there is almost this sentiment of anger on the various message boards about how GM duped us.
I don't see how. Nobody likes being lied to. Not investors, not customers, and I assume not regulators. Screw GM for this cynical BS.


RE: drivetrain shrink
By ianweck on 10/12/2010 11:21:51 AM , Rating: 2
GM hasn't duped anybody. The DailyTech article is the problem. Try researching a topic outside of DailyTech before just jumping to conclusions.


May not be a bad idea
By HoosierEngineer5 on 10/12/2010 9:07:51 AM , Rating: 2
Using the planetary gear system, any power not being directed to propulsion can be directed to the motor-generator which can be used to charge the depleted battery, or provide pre-heat to them. This allows the infernal combustion unit to operate near peak efficiency.

Additionally, if the electric control system catastrophically fails, you have a conventional engine driven system to get you to the service center.




RE: May not be a bad idea
By mindless1 on 10/19/2010 3:57:30 PM , Rating: 2
No it is the opposite. An engine set up to operate at steady load charging a battery is MUCH more efficient than one that has to operate through a transmission to provide propulsion.

That was the point all along, to avoid varying engine RPM and load efficiencies and only operate it at peak efficiency coupled with a generator that was spec tweaked to be the right load on the ICE for that... and the same is true of any ICE engine and always will be.


Bait and switch?
By ianweck on 10/12/2010 11:18:51 AM , Rating: 2
Wow Jason. I've read from other posters on other threads about how you can be either purposefully deceptive or just outright not know what you are talking about, but I had never really believed it until now.
Here is how it actually works:

quote:
"The drivetrain has a bit in common with the Prius and Ford hybrids. It consist of a single planetary gearset, two electric motors, and one gas engine. Motor Trend thinks the design is superior and more efficient than Toyota’s, and according to GM engineers with whom I spoke, is on the verge of patented.

There is a large central sun gear turned by the 149 horsepower electric motor at all times. Around it is a planetary carrier which turns the wheels. When the car is in charge depleting mode, an outer ring is locked to the case. The engine and generator are disengaged.

When the car reaches 70 mph the main motor spins too fast to be maximally efficient, and a clutch disengages the ring from the case. This allows the second electric motor to participate and both motors act in parallel to reach speeds of 101 mph with adequate power.

In charge sustaining mode, the gas engine goes on and clutches to the generator causing it to produce electricity to continue powering the main motor.

However of particular interest, when going above 70 mph in charge sustaining mode, and the generator gets coupled to the drivetrain, the gas engine participates in the motive force. GM says the engine never drives the wheels all by itself, but will participate in this particular situation in the name of efficiency, which is improved by 10 to 15 percent."


If you read carefully, it actually says that the electric motor will always power the wheels except in one condition: charge sustaining mode above 70 mph. Even then the gas engine is only assisting and isn't the sole source.
So in my opinion that's hardly a bait and switch.




RE: Bait and switch?
By mindless1 on 10/19/2010 4:02:14 PM , Rating: 2
In my opinion it's clearly bait and switch. IF it had cost closer to a plan ole ICE car I would have considered buying one, but THIS?

This is a frankenstein mobile, if you have the ICE engine and put a transmission on it to propel the car, then adding the weight, expense, and complexity/repair cost/frequency of the electric motor addition and battery pack is stupidity.

They basically removed even the virtues that even bubbleheaded green-fiends liked, now it is just a nonsensical feel good product with no point.


New opportunities
By US56 on 10/13/2010 2:42:13 AM , Rating: 2
Unfortunately, the deception, or disinformation if you prefer, may create opportunities for class action lawyers unless the sales agreement they've been using has sufficient weasel words to give them plenty of wiggle room to the effect that they are free to change the specifications without prior notice. Of course, their problem is automatically your problem if you're a federal taxpayer. GM has also stated that they wanted to float their IPO sometime between late October and Thanksgiving. Aside from current market conditions not being very conducive to many an IPO it's probably not a coincidence they did the big reveal just weeks before their hoped for window of opportunity. Had they waited until after the IPO they would have had potential legal exposure there as well. Now they will probably only have to redo some of their full disclosure which might delay the IPO. Previously, my only interest in the Volt has been discomfort at being, in effect, an unwilling, captive investor with little or no possible return on investment. However, the patent filing for the GM EVT technology which seems to be the core IP of the true Volt design reveals some interesting tricks which are apparently not being exploited in the first gen model. That would seem to create opportunities for those who enjoy tweaking and hacking to apply their skills and attention to the new product.




RE: New opportunities
By mindless1 on 10/19/2010 3:54:11 PM , Rating: 2
Do you realize that if you don't even try to format your post, it just looks like the rantings of a shallow mind because nobody feels like reading it to be convinced it is more than that?


Lame and disappointing
By tallguywithglasseson on 10/11/2010 3:44:39 PM , Rating: 3
Not to mention deceptive.

GM's on a roll. I'm not really all that interested in this project/vehicle anymore. The main reason I was intrigued was its supposed underlying tech, the "range extended EV" or "series hybrid" or whatever you wanted to call it.

Is anything they've said about the Volt true? If that *is* its real name?

I'm trying to get inside the heads of the guys who thought deceiving the public and automotive press for years was a good plan. The reasons they gave just aren't doing it for me.




Detroit News Are Morons?
By azcoyote on 10/11/2010 5:01:50 PM , Rating: 3
quote:
The Detroit News writes: After I drove more than 32 miles on electric power only — in a very un-eco-friendly manner — the Volt’s little engine began powering the car. This was the moment I had been waiting for: It’s one thing to power a car with batteries, but it’s revolutionary to have a gas engine supply the power to electric motors. The succession of power is more seamless than a presidential election. The engine is quiet and keeps humming along. There’s never a glitch, a pause or a moment when the engine noticeably kicks on or off. For the most part, once the initial battery charge is drained, the engine produces the electric power to drive the motor.


Excuse me but doesn't this article say exactly the OPPOSITE?

It is a hybrid not BEV.




Government Motors...
By mmatis on 10/11/2010 6:41:36 PM , Rating: 3
lies again! Quelle surprise!




Not really a problem...
By Marlonsm on 10/11/2010 2:57:28 PM , Rating: 2
It might actually increase the efficiency.
When the batteries are low, instead of only:
Engine-->Generator-->Battery-->Motors--& gt;Transmission-->Wheels
Now, part of the power is just:
Engine-->Transmission-->Wheels
Less steps means less power lost and more power where it really matters.
That is, assuming they get the engine to always run in a optimum RPM or close to it, increasing the efficiency even further.

Although I dislike GM's attitude of hiding it for so long.

Now, real innovation would be using a jet engine to generate electricity, as it has a great efficiency in a very narrow range of RPMs. Let it run in the best RPM and let a generator, a battery and some motors do the rest.




Another reason for new layout
By pityme on 10/11/2010 4:58:18 PM , Rating: 2
A key consideration with any battery system is the number of charge/recharge cycles. With proper system setup, the new layout of mechanical drive could minimize the charge recharge cycle substantially. Since the batteries are a main driver in initial and reoccuring costs, this is a major issue also.




Parallel & Serial
By clovell on 10/11/2010 5:04:23 PM , Rating: 1
I wish you could use the actual nomenclature that was used all through research & development rather than disfiguring the discussion with never-really-used-before terms like BEV.

Nobody ever thought the Volt was a BEV. We all knew it to be a Serial-PHEV the whole time. Now, we're finding out it's actually a Parallel-PHEV.

What I actually want to know is how the hell they pulled this off. Toyota's Synergy Parallel drive is a modern masterpiece in engineering, perfected over several product generations. Half the reason I had faith in the Volt was due to its simpler, more elegant Serial design.

You'd do well to edit the article, Jason. The informed readers are gonna deep fry you.




RE: Parallel & Serial
By sethenon on 10/11/2010 8:12:46 PM , Rating: 1
This is a sensationalist headline and poorly written article if I have ever seen one. For a more informed point of view check out this article:

http://www.thecarconnection.com/marty-blog/1050307...


WTF?
By ezinner on 10/11/2010 9:19:31 PM , Rating: 2
How can GM tout the benefits of the combustion engine being used only to charge the batteries for the last few years and now change their tune?




Uh, please do your research...
By sgtpokey on 10/12/2010 11:35:35 AM , Rating: 1
For something more informed and balanced, the carconnection definition will leave anyone interested with a much better understanding of what the Volt is doing. For those responding to the DailyTech post without additional digging, you can get your short summary below:

---

Semantic sand castles
Does that mean it's not an all-electric car the rest of the time? No. It just means that in addition to being an all-electric car, it has some hybrid-like capabilities. So Chevy delivers an EV with 340 miles range and adds in a power boost to maintain highway speeds even when the battery is discharged...and the media complains about it? This does not compute.

Put another way, if you drive your LEAF toward the end of its battery range, even if you have a charger waiting at the other end of the road, it'll stick you in a speed-limited "limp home" mode. The Volt's "limp home mode" lets you drive on the freeway at the cost of a little electrical purity. The arbiters of Green Morality may cringe, but at least you'll make it home in time to get the kids to soccer practice.

The "GM lied" fanatics can build their semantic sand castles and kick down GM's own all day long, but at the end of the day, this "lie" means the Volt is more capable than any other vehicle in its class. Is a flashy headline really worth dragging what may be the best EV/hybrid/futuremobile/whatever through the mud over a case of dubitable nomenclature? Apparently, to some, it is.

http://www.thecarconnection.com/marty-blog/1050307...




RE: Uh, please do your research...
By sgtpokey on 10/12/2010 11:39:13 AM , Rating: 1
roudnign out quotes from the car connection:

What the Volt really is
So what is the Volt? For the first 40 miles (and every 40 miles after that, if you're in the target market sweet spot) it's a pure EV. If you want to treat it as such, it's simply a battery EV with a 40 mile range and a lot of extraneous hardware. Unlike the LEAF or any other number of battery EVs, it won't leave you stranded if you get out too far without an outlet nearby. And unlike any mass-market hybrid, you can simply charge it each night and go about your 40-miles-or-less daily business without ever dipping into the world's diminishing supply of dinosaur juice.

Instead of either the battery-only EVs or the standard/plug-in hybrids, the Volt takes a scene from the heavily-sponsored Transformers movies and becomes an EV that generates its own charge from an on-board generator. Drive it around town, it's still powered purely by the electric motors. It's still an EV, just drawing its power from its own portable grid. Remember--the grid the LEAF and all other EVs pull their power from burns a considerable bit of coal to produce that electricity, too, but you can't put a coal-fired powerplant in the back of a LEAF. Sure, the gasoline engine isn't as efficient or as clean as a powerplant, but now we're talking differences of degree, not of kind.

But imagine now that your Volt has run out of its battery power, and your return trip necessitates some highway driving. Instead of saying "no sir, charge isn't high enough for highway speeds," the system dutifully kicks in and adds a little boost from the combustion engine, allowing you to flow with traffic rather than being an eco-friendly rolling road block. Convenient, confidence-inspiring, and, by the way, something none of those other EVs can do.


Mindless
By mindless1 on 10/19/2010 3:49:57 PM , Rating: 2
Perhaps some don't understand mechanics, it is NOT a good thing to have the transmission involved. It is a significant weight addition, additional mechanical parts likely to break down (especially with the emphasis on weight reduction), and very very likely to be a premium expense to repair compared to anything but the eventual battery replacement.

To put it another way, this reduces the car to a piece of crap. Literally, someone could just make wheels with the motors in them, you shove a big battery on your back seat, and then a huge alternator under the hood and you have the same thing though with a bit higher center of gravity.

Point is, this reduces it from revolutionary to a step backwards at a premium price!! Yes you read it right, this will use as many resources over it's lifetime, cost more over it's lifetime, be in need of repair more often, and be totalled, ending up a waste in a junkyard more often.

Isn't that a great deal? Pay 50% more for a car then scrap it 50% sooner while paying 50% more to maintain it till then?

WOOHOO for progress.




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