Filed under: EV/Plug-in, Hybrid, Chevrolet, GM, Legislation and Policy
GM reaches agreement with CARB on unique classification for Volt
Ever since the Chevrolet Volt appeared as a concept last year, debate has been hot and heavy over exactly what it is. Although many call it a hybrid because it has a battery and an engine, GM prefers to call it an extended range-electric vehicle (ER-EV). That poses a problem for GM when it comes to emissions and fuel economy testing. With its 40 mile electric only range the Volt could complete the US06 test cycle that is part of the current EPA test regimen without ever running its engine. So far this doesn't sit well with the EPA which considers the Volt a hybrid and expects it to complete the test cycle with a charged battery. GM and the feds have been going back and forth on this for months. Reports out this morning on Bloomberg and the Detroit Free Press indicated that GM and the EPA had reached an agreement that would potentially see the Volt as the first car classified with a 100 mpg rating are erroneous. We called spokesman Rob Peterson to get the scoop, and it turns out that GM has reached an agreement with the California Air Resources Board, (CARB) on a unique classification for the Volt. Peterson told ABG that this classification would reflect the Volt's true capability, essentially treating it as an EV. According to Peterson, "the classification helps us to optimize the Volt for what it does do, instead of being put into the category with a normal hybrid." This will potentially allow GM to run the Volt with the planned charge sustaining mode rather than having to run the engine to fully recharge the battery at the end of the test.
The agreement with CARB gives GM a bargaining chip in its talks with the EPA, but Peterson cautions that the automaker and the federal agency "still have a long way to go" to finalize any agreement. The Volt may yet get that magic 100 mpg rating, but it's not there yet.
Gallery: 2011 Chevrolet Volt Live Reveal
[Source: General Motors]
Reader Comments (Page 1 of 2)
jzj 3:02PM (9/26/2008)
Ultimately, energy requirements and fuel source are the only determinants for a vehicle's efficiency (excluding the variable of the driver's right foot). Since we are now moving into different waters with the advent of ER-EVs, it's a good time to revisit the whole ratings issue. I would propose the following: 1. Rate vehicles based upon their inherent energy requirements -- how much energy it takes to idle it, accelerate it at some standard measure, decelerate it at some standard measure (this could be a plus!), and keep it rolling down the road at some standard measure (ex: it takes 10KW (or whatever) to move this vehicle down a level road at 100kph at such and such standardized temperature and air pressure); 2. Identify the vehicle's potential fuel sources -- gasoline, diesel, alcohol, electricity from coal, electricity from natural gas, etc. -- and based upon their energy requirements, determine how much pollution they would create using their respective available fuels.
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GoodCheer 4:25PM (9/26/2008)
The Volt only has itsy-bitsy side windows.... Just how big do you want the window sticker to be?
Anth 3:03PM (9/26/2008)
How would one smog check a Volt? You'd have to manually turn the engine on to get a reading.
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rgseidl 9:56AM (9/28/2008)
If a vehicle cannot be smogged, it cannot be sold in states that require such a check on emissions from the ICE. Therefore, I'm sure the engine service port will provide a feature that lets the operator override the regular control logic and force the engine to fire up. Indeed, customers may insist on this, if only to make sure the engine and three-way catalyst can get up to temperature before the smog test.
As for the classification, I think any attempt to characterize fuel economy with a single number is doomed to fail. The whole notion of MPGe is ok for a straight diesel or CNG drivetrain but E-REV completely breaks it because actual fossil fuel consumption depends entirely on trip length between recharge opportunities.
Instead, authorities should start with a charged-up battery and repeat their test cycle until the engine controller signals it's about to fire up. At that point, the the test is interrupted and reset to proceed as usual. This combo will establish expected all-electric range on grid electricity as well as fuel economy in charge-sustaining mode.
If required, the indirect CO2 emissions associated with charging up on grid electricity should be based on the generation mix in the state in which the vehicle is offered for sale. That means the showroom stickers will vary from state to state. The requisite data is independent of the vehicle test and should be available from DOE in terms of kg CO2/kWh. A little math can translate that into g CO2/mile in the test cycle to permit a direct comparison with GHG emissions in charge sustaining mode. Similarly, cost per mile need to be listed separately for all-electric and charge-sustaining modes.
All this extra data will make it a little harder to interpret the results and compare them to conventionally powered cars. Such is the nature of the beast.
Btw: for the results to be useful to consumers, the manufacturer will need to provide additional data to support its claim that the battery pack's depth of discharge levels at the outset and when the ICE fires up guarantee the life expectancy required of emissions reduction equipment.
Anth 10:39PM (9/28/2008)
Very true with the MPG rating breaking. I actually mocked up a new window sticker that was designed for the Volt and other EREVs. The MPG rating has to go out the window..
http://www.sequence-omega.net/2008/09/07/chevy-volts-mpg-rating/
In a later post, I said that the bottom table area should be replaced with a gallons per x miles chart. To show that from a full charge, 100 miles consumes about 1.25 gallons, 50 miles is a little over .2 gallons, etc.
gorr 3:12PM (9/26/2008)
Why wait 2 - 3 years for this miracle car while hydrogen cars are ready from the majority of auto manufacturers? Im sure gm,ford,chrysler have accepted 25 billion$ in subsidies to stop hydrogen implementation.
They look more and more like old farts waiting to be feed by taxpayers.
Its the rising price of gasoline that make the american manufacturers in a very bad situation. Only battery technology is allowed by your goverment because it's not a good solution. No big rig can be power by battery. Hydrogen gas on the other hand can replace petrol in everything without pollution..
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meme 3:22PM (9/26/2008)
"Why wait 2 - 3 years for this miracle car while hydrogen cars are ready from the majority of auto manufacturers?"
Thanks for the laugh; I needed it. :)
"No big rig can be power by battery."
You mean, except for the multiple ones that AutoblogGreen has repeatedly reported on for the past several years? Compared to the zero hydrogen big rigs (because the fuel cell price would be 7 to 8 figures)?
"Hydrogen gas on the other hand can replace petrol in everything without pollution.."
No pollution except for that created by its requirements for three times the energy as EVs.
AMcA 8:26PM (9/26/2008)
Yeah, gorr!
Tap the hydrogen mines now!
There are no hydrogen mines? No way.
We need to put huge amounts of energy into making hydrogen? OK, then use water engines to generate it!
Chris M 2:29AM (9/27/2008)
By "ready" you mean those extravagant million dollar prototypes? Sorry, but there isn't much of a market for cars that cost more than most homes, run on an expensive fuel with limited availability, and have modest performance and range.
Glenn 2:39PM (9/27/2008)
Electric cars are so much farther along, by any measure, than are hydrogen cars.
The only reason for hydrogen is as a delay tactic by the car companies. As long as gas was cheap, they profited immensely by the status quo.
paulwesterberg 3:13PM (9/26/2008)
ICE engines are typically only 20-25% efficient. The toyota prius gets its mileage boost through constant engine rpm, regen braking, low drag & rolling resistance and not idling at stop lights. The prius gets 50mpg with all of its energy coming from gas with an ice that still wastes 75% of the energy as waste heat.
Lithium batteries and electric motors are 85-90% efficient, so if you take the electrical energy equivalent of a gallon of gas and use it to move a prius like EV you should be able to get 170-200mpge and end up paying less than $4 to travel 200 miles.
The volt doesnt have a battery pack big enough to store the equivalent of gallon of gas worth of electricity. It can only store 40 miles worth(24% of a gallon) so that means its overall efficiency is blended and depends on how much charge the battery holds. Its efficiency after the battery is depleated should be at least as good as what the prius gets.
If you start with a charged vehicle and run it until you use one gallon of gas equivelent you would use:
- 40miles on electric uses 24% of 1 gallon equivelent.
- 50mpg*76% of a gallon -> 38 miles on gas.
40+38 = 78mpge combined for the first gallon.
Also I expect that when in range extender mode the volt with new technology and lithium ion batteries could improve efficiency 5-10% over the 5 year old prius design.
Since most people drive less than 78 miles on an average day they will often use more electricity than gas which will improve the actual efficiency and further reduce the amount of gasoline needed to fuel the vehicle. So an argument for 100mpge could be made.
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Paul Sallmen 3:18PM (9/26/2008)
It goes without saying that the Volt is a little different. More and more EV-Rs will come out after the Volt, so a proper way to show its efficiency is needed. The '100 mpg' label looks nice, but it doesn't really show how the Volt works, ie that it won't use gas at all on short trips. That's why there should be 2 fuel economies listed: The fuel economy when the gas generator is required and the fuel economy when the gas engine in not needed:
For example:
Fuel economy with gas generator used 100% of the time:
50 mpg / 4.5 L/100 km CITY
47 mpg / 5.0 L/100 km HWY
Energy usage for electric mode:
1000 Wh/km
Range for electric mode:
40 mi / 64 km CITY
37 mi / 60 km HWY
The Wh/km (Watt-hour per kilometre) rating will be useful when more EVs come on the market as one will be able to compare the efficiency of the electric engine more easily. Initially, the Wh/km number will have no meaning as this will be the first EV to be rated, however, overtime people will begin to notice the differences. I also think that even America should use Wh/km (instead of Wh/mile). American businesses have long understood the benefit of using metric since it is the world standard. Since this will be a new measurement (for EVs), its implementation should be non-controversial.
In addition, the fuel economy label should indicate an approximate annual cost, with a certain price determined for gas and electricity. Again, 2 numbers should be given - one for when the car is never plugged in and one for when it is.
Note: the numbers I pretty much pulled out of a hat, as I don't know what the actual efficiency will be.
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Mike Weston 4:11PM (9/26/2008)
I like Paul Sallmen's proposal.
For people that insist on an MPG number, you could set a fixed conversion rate based on national average electricity rates and gas prices, and then at the end of the test charge it back up to the original level and convert that to gallons of gas. You would have to change the conversion rate every year though, so Paul's suggestion is technically better. I just worry that people are too lazy to understand it.
Geoff de Ruiter 5:08PM (9/26/2008)
I posted on the same topic a while back and came to the same conclusion as Paul. 3 pieces of information. 2 main ratings W-h/km for EV mode (translatable to the fully EV models) and MPG (or L/100km) for when under hybrid mode just like other hybrids, then the added range of EV again translatable to fully EV models. If they do any other way it'll eventually cause too much confusion with percentages of renewables. 100% coal/oil/nat gas ok fine MPGe, but 100% renewable energy (solar, wind, geothermal) MPGe 100% does not work at all.
meme 3:18PM (9/26/2008)
jzj: I mostly agree with you, but there are some other issues. A gas car and diesel car may have the same energy requirements to move, but the diesel car will convert the potential energy in its fuel to kinetic energy 25% or so more efficiently.
Because of things like this, I prefer rating cars by multiple stats -- Wh/mi, electric range, gallons per mile in charge-sustaining mode, and g/mi CO2 for electricity and for gas. Yeah, it's not as easily summed up, but at least it tells the truth -- not some made-up combination figure like "100mpg" that's, by all standards, useless. It doesn't tell you how much environmental damage you're using, how much it'd cost you to drive around town, to go on a road trip, how far you can go gas free, etc. It's just useless and, not to mention, misleading. It makes people think that they could cross the country on 30 gallons of fuel, without letting on that to do that, they'd have to stop to charge every 80 miles.
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Throwback 3:26PM (9/26/2008)
I think a multiple rating for the Volt makes sense. 40 miles electric only range, 50 mpg (or whatever) after 40 miles. For pure EVs "X number of miles per charge under ideal conditions". The conditions would have to be spelled out, i.e. temperature during the test, no accessories used (I assume everything will be electric) and city and higway mileage.
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PeterG 4:40PM (9/26/2008)
So GM gets a chunk of 25Billion Bailout.
The get a Volt specific tax break passed.
And now they are pushing to be able to lie about fuel economy.
Gahhh. This kind of crap makes me cheer for GM's demise.
Burn GM, Burn.
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jzj 4:47PM (9/26/2008)
Meme: Thanks, but perhaps I wasn't sufficiently clear so let me cut it down to its basics: the ratings should only be re 1. energy needed 2. pollution created. That way, it bypasses so much other information in favor of just showing the energy required to move a vehicle around and the pollution that movement will cause depending upon the fuel source it uses. If it can use multiple sources -- and if you think about it, most cars can use multiple sources whether its gas and electric, or gas and (mostly) alcohol, or petro-diesel and bio-diesel -- then rate it based on those sources.
Really, I'm going to guess that you never need do any imperical road testing: look at the aerodynamics and test-bed rolling resistence of a car and then one should be able to calculate its energy needs for acceleration and steady state driving. You would have to idle the car to determine its idle efficiency and test the engine to determine its specific consumption and pollution levels when making the necessary power for acceleration and steady state driving, and then just look at charts to see how much pollution you'd be creating for various fuels available to that vehicle.
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Rick 5:10PM (9/26/2008)
The Volt loses the tech war to "conventional" hybrids.
It looks like for some people Chevy just created a car they won't want. Unless, that is, they have another car for driving beyond the 40 mile limit.
The 1400cc engine, which is about the same displacement as a Prius engine, does not regenerate the batteries nor does it have any of the other hybrid appeal for long distance driving. Instead the engine is a backup system to be used when the batteries are depleted. At that point, the batteries and drive system they represent, are dead weight that the 1400cc engine carries with it. This suggests that gas mileage beyond 40 miles would be less than if it didn't carry that weight around.
For short trips this is may be fine but anyone that wants to take mini vacations on the weekends on any regular basis this will probably be a put off.
As a 2002 Prius owner that doesn't want to own two cars at a time, the Volt, as currently spec'd, seems to be an unreasonable compromise.
It is hard to see how the EPA would consider this a 100 mpg vehicle without completely redefining the measure to include distance.
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fnc 7:46PM (9/26/2008)
"At that point, the batteries and drive system they represent, are dead weight that the 1400cc engine carries with it. "
The batteries allow recapture of braking energy and give an extra jolt during acceleration and climbing which means you can get by with a smaller ICE for steady state driving. In other words, the Volt in charge sustain mode benefits from having batteries in exactly the same way the Prius and other parallel hybrids benefit from them. Perhaps moreso considering that the serial nature allows the engine to run steadily at its most efficient RPM.
As far as GM wanting to say "100 mpg" it's a little disappointing. If anything, GM should be calling for an entirely new rating system which would strongly highlight the fact that this car is fundamentally different from anything before it, the game changer it's been called. While "100 mpg" might say "super efficient" to a lot of potential customers, "NO GAS NEEDED FOR 40 MILES" would be a much stronger selling point to a lot of people. It's not like that fact won't be noted and touted by any dealer selling them, but a car calling for a new rating system would get GM a lot of very good press out of the deal.
I agree with the others, it may be time to fundamentally reassess how we rate the efficiency of a car. If electrics become more prevalent, "MPG" will become a more and more meaningless term.