GM Switches Gears...Thinks Green

<div class='quotetop'>QUOTE(john1701a @ May 29 2007, 01:14 PM) [snapback]451512[/snapback]</div>

I'd like to take a swing at that question, as to why a series hybrid might work better as a plug-in car. I've been studying the Hymotion Prius PHEV conversion pretty closely and hope to purchase one in 2008. Some studies by Argonne labs and others have highlighted a few unintended negative consequences of using a parallel hybrid like the Prius as a PHEV.

(One moment to be clear: I mean series to be a hybrid where the ICE only charges the batteries, and only the electric motor drives the wheels. I mean parallel to be a setup like the Prius where the ICE is needed to drive the wheels directly under heavy load, such as rapid acceleration or sustained highway driving.)

As currently configured, a PHEV Prius will end up running the ICE fairly often in routine driving. That's what Argonne says, that seems to be the case with the CalCars conversions and with one PHEV Prius (Hymotion conversion) being run by Fairfax County, VA. Based on what Argonne and others have said, this means:

a) If you don't run the ICE routinely to keep it warm (which is the Hymotion setup - do not keep the engine warm), routine driving will result in somewhat more unburnt hydrocarbons and more NOX than a stock Prius, per mile. The ICE runs cold so it runs dirty.
b) If you do require keeping the engine warm, the fraction of transport that is using wall-socket-electric for the energy source declines.
c) You'll have to run the engine in winter to provide cabin heat (at least in a a stock Prius conversion).

In addition, unique to these add-on setups like Hymotion, the Prius won't charge the battery while in PHEV mode, so you lose that "hybrid efficiency" while driving -- can't load the ICE optimally, so the ICE use may be less efficient than it would be in a stock Prius.

But the biggest problem is that if some of the miles have to be ICE miles, in routine driving, that means you can never tap into very clean, very efficient all electric miles. So the maximum efficiency of the vehicle is limited, even for short trips. You can't take a 20 mile battery pack, go 20 electric miles, then recharge it. You have to go 35 mixed miles, then recharge it.

All told, the PHEV Prius mileage numbers seem to cluster around 85 - 95 mpg-equivalent, based on cost. (That is, the cost of fuel (gas + wall-socket) is about the same as an 85 mpg car). Calcars gets 85, Argonne reported (I believe) 95, and the Fairfax County PHEV Prius reported some trips in the 90's (but that's gas mileage, not total energy cost). The upshot is that the PHEV Prius conversions give a reasonable jump in fuel economy (combined gas + electric cost) but not and overwhelming jump. (And they do in effect substitute coal (or other electric power fuel) for gasoline, so they do reduce need for oil).

All of these issues go away (except possibly cabin heat) in a Volt-like serial hybrid. Because it doesn't need to run the ICE to push the car in routine driving. So a serial hybrid like the Volt, if it ever is built, might be a preferred approach for people who want electric-only miles. People whose driving would fit under the (e.g.) 20 mile pack limit should be able to get much better mpg-equivalent mileage out of a serial hybrid than out of a PHEV Prius.

My opinion is that a Volt with a 40 mile pack, with an automatic HOV sticker, would be an absolute category killer of a commuter car. I'm not GM fan (my first car was a Chevy Vega, 'nuff said), but if GM can make this at some reasonable price I'd expect it to be a huge winner.

 

<div class='quotetop'>QUOTE(Fibb222 @ May 29 2007, 03:42 PM) [snapback]451661[/snapback]</div>

That became all too clear back in 2001.

The engineering and production was proceeding just fine. Dealers were the hold up. Some of them impaired rollout success. It was very frustrating... but makes for good blog reading now, 6 years later!

 

The "series" hybrid still leaves a number of major questions unanswered, like how much range you'll lose in the winter due to both reduced battery-capacity in the cold temperatures and the draw from an electric heater.

The pure electric approach most definitely is appealing though. But it's compromises aren't as clear yet, making the already proven "full" hybrid a much safer large-scale bet for the masses in the very near future.

Business risk is tricky. Volt is quite a gamble currently, especially with real-world efficiency being so uncertain. The "full" hybrid makes the step to follow considerably easier.

 

One question I have about the Volt - is GM going to sell them or lease them?

Ducking for cover...

 

<div class='quotetop'>QUOTE(Proco @ May 29 2007, 12:20 PM) [snapback]451521[/snapback]</div>

Actually, in the past 20 years or so, the 'Big 3' have caught up a lot on reliability... at least according to Consumer Reports. When I was looking for a new car two years ago, Ford, GM and Chrysler all rated higher (albeit SLIGHTLY) than BMW or Mercedes (I believe the category was # of reported problems per 100 cars after 5 years, with Big 3 coming in around 35-40 vs. 45 and 50 for European makers). Honda and Toyota still owned the overall reliability however with 5-10 per 100 though. And yes, I know all about DaimlerChrysler

 

Many years back, Toyota set a goal of building 300,000 hybrids annually. That was met & exceeded. Now the bar has been raised to 1,000,000. That's realistic. Deeply penetrating the market that way will really make a difference.

What exactly does "Think Green" actually mean?

How big of an impact will Volt make? An annual production of just 60,000 and no other "series" hybrids to choose from would be disappointing, especially after waiting several years for it. Will GM push to make it more popular? If so, how will they handle the backlash from an inevitable desire for the technology to be available in other vehicles? And how what will they do with promoting Two-Mode in the meantime?

From the WSJ article: "Two hybrid SUVs are due late this year with a system that GM believes has advantages over Toyota's hybrid technology. But GM only expects to sell a few thousand, while Toyota is counting on selling 250,000 hybrid vehicles in the U.S. this year, including 160,000 Priuses."

In other words, the intentions of GM remain a mystery... which I suspect is what contributes to the perceived hate. We want to know what the plans are.

 

<div class='quotetop'>QUOTE(john1701a @ May 29 2007, 01:14 PM) [snapback]451512[/snapback]</div>

Volt is more electrically dominant than Two-Mode. We still have yet to see a Two-Mode hybrid but GM has been "educating" the public that the advantage of it's Two-Mode over HSD is the smaller/weaker electric motor, thus lowering the cost. Hence the problem of plug-in solution for the Two-Mode design -- electric motors are too small to realistically accelerate the car/SUV. I suspect Prius' 50kW electric motor will be more powerful than Vue Two-Mode hybrid.

Prius is not a parallel hybrid. HSD has characteristic of both parallel and series hybrid. I say HSD is a more "fuller" hybrid than Two-Mode design. Can GM make Two-Mode with larger and more powerful electric motor? Maybe but the size will be so large because of the extra planetary gearset and the clutches -- it might defeat the purpose of the Two-Mode.

I think GM need Volt to make a plug-in that can accelerate well and go further. Will Toyota have a pure Series hybrid design? I am sure they do. Unlike GM, Toyota will not talk until they are ready to sell.

To answer your question, I can not compare Volt and Two-Mode plug-in since they don't compete in the same plug-in speed or range.

 

<div class='quotetop'>QUOTE(usbseawolf2000 @ May 29 2007, 09:48 PM) [snapback]451829[/snapback]</div>

Long-Term (a good decade from now) that will be a clear benefit. But in this market, with the automakers struggling to overcome their past, that's not the case. Battery technology is still advancing by leaps & bounds too. Power management is being fine tuned as well.

In the meantime, I have a fascination with how some have already drawn a conclusion that "full" hybrids don't stand a chance. True, some will exhibit advantages over others. But the unexpected results from real-world driving makes it really exciting. And how consumers in general will respond is anyone's guess.

Short-Term, the goal of making "full" hybrids commonplace is realistic... and green, unlike some of the "assist" hybrids. In other words, jumping immediately to "series" is an extraordinary challenge. Lots still has to happen before that.

 

"Who Killed The Electric Car" That'll tell ya where GMs business is going. That'll show how viable the Volt is to making production. I'm no GM fan, don't care to be. Crushing perfectly running NON-GASOLINE vehicles? Can you say threat to national security? But, hey, they've made a killing in their SUV market.

 

<div class='quotetop'>QUOTE(finman @ May 30 2007, 10:45 AM) [snapback]452095[/snapback]</div>

Lots of people have thoughts about that... but few address the rest of the world. What happens in "America" may or may not have much impact everywhere else.

How many vehicles does GM sell in Japan?

What do consumers want in markets where the electric-grid is still developing or in dense urban centers without parking-lot plugs?