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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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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.


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