Chevy Volt Barely Makes 2011 List of Greenest Vehicles

By · February 17, 2011

Chevy Volt

To evaluate the green-ness of the Chevy Volt, ACEEE looked at many factors, including vehicle weight—as well as typical American driving patterns to determine how often the car would run on gasoline versus electricity.

The American Council for an Energy Efficient Economy’s Green Book is the bible of environmental rankings for cars and trucks. And the 2011 issue, the 14th annual edition, just hit the streets. “This is the most exciting Green Book in a decade for me, because there are so many vehicles in the running,” said Therese Langer, ACEEE’s Transportation Director, in an interview with The non-profit uses an exacting methodology for calculating the environmental impact of all cars and trucks.

Despite new competition from electric vehicles, such as the all-electric Nissan LEAF and the Chevy Volt plug-in hybrid, the winner for the 8th consecutive year is the Honda Civic GX, which runs on compressed natural gas. “The Chevy Volt came very close to not making the list,” said Shruti Vaidyanathan, ACEEE Vehicle analyst. The first negative mark against the Volt in ACEEE’s methodology is the weight, which provides an indication of how much energy went into producing the vehicle. The Volt weighs about 500 pounds more than the Nissan LEAF or Toyota Prius.

The non-profit also took a hard look at the Volt's operation on the road. “The Volt running on gasoline doesn’t have terribly impressive fuel economy. It’s rated at 35 mpg in the city and 40 highway,” said Therese Langer, ACEEE’s Transportation Director. “If you think of it as a vehicle that is roughly two-thirds electric and one-third gasoline, as an electric vehicle it does pretty well, but not quite as well as the LEAF.”

The "two-thirds EV and one-third gas" approach stems from data about typical driving patterns of American drivers, as used by the Society of Automotive Engineers and the Environmental Protection Agency.

“As a gasoline vehicle, the Volt does okay, but there are a whole lot of gasoline vehicles that beat it out," said Langer. "So when you take the fact of those two things together, it comes out about where you think.”

LEAF is Winner in Certain Parts of U.S.

While the Civic GX took top honors, the Nissan LEAF was an incredibly close second place—coming within 2 percent of ACEEE’s calculations for environmental impact. When you consider that ACEEE uses a national average for the green-ness electricity generation, the Nissan LEAF becomes the clear winner in parts of the country where electricity is made mostly from renewable sources.

The diversity of auto technologies and drivetrains is striking in this year’s Green Book. The top four slots are made up of a vehicle running on compressed natural gas, an EV, a small internal combustion engine vehicle, the Smart ForTwo, and the Toyota Prius, a conventional hybrid.

Honda Civic GX

The Honda Civic GX, which runs on compressed natural gas, was rated the greenest vehicle in America for the 8th consecutive year.

The Smart ForTwo leapt ahead of the Prius and the Civic Hybrid because ACEEE shifted its methodology to utilize version 2.7 of the Argonne National Labs GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation) Model. In prior years, the battery of a hybrid or electric car was scored for weight just like any other component of the car. But with the new GREET methodology, batteries are considered to have a greater environmental impact, because of the energy and other resources required to manufacture the batteries. As a result, hybrids took a hit in 2011.

Nonetheless, the Prius, Honda Civic Hybrid, and Honda Insight ranked fourth, fifth and sixth respectively. The rest of the list was made up of small internal combustion cars: Ford Fiesta SFE, Chevy Cruze Eco, Hyundai Elantra, Mini Cooper and Toyota Yaris. And taking the final spot in ACEEE’s Top 12 Greenest Cars is the Chevy Volt.

Update 2/17/11: On Feb. 16, ACEEE corrected two mistakes in its calculations. The 2011 Toyota Prius uses a 1.8-liter engine, not a 2.0-liter as previously noted. More importantly, the Chevy Volt is certified as a Bin 4 / ULEV II, not a PZEV. As a result, the Volt drops to 13 in the list, and is bypassed by the Mazda 2.

2011 ACEEE Green List

Other vehicles that nearly match the environmental score of the Volt, but that did not make the top 12, are clean diesel versions of the Volkswagen Golf, Volkswagen Jetta and Audi A3; the hybrid Honda CR-Z; and the gas-powered Mazda2.

Tougher Competition for Top Spot Next Year

When asked how much longer the Civic GX could maintain its top position, ACEEE researchers pondered that the competition is going to get even tougher next year. Vaidyanathan pointed to the upcoming Smart ED (Electric Drive), which already scores well as a gasoline car; and the plug-in Prius, which already scores well as a conventional hybrid without plug-in capability. By running on electricity instead of gasoline, both of these cars have a chance of taking the lead position in 2012.

The 8th consecutive victory for the Honda Civic GX hopefully will draw attention to the model, which is the only compressed natural gas vehicle in U.S. showrooms. Last year, Elmer Hardey, Honda’s senior manager of alternative vehicles, told that the Honda Civic GX will become an even more important option for the upcoming 2012 redesigned Civic. “With all the activity in the environmental vehicle space, we’re anticipating growth in sales of CNG vehicles, not only in California but nationwide,” said Hardey.


· · 7 years ago

What a total crock of s***! How a 33/41 mpg 2-seat Smart beats out a 51/48 Prius it complete nonesense. Something here is very strange. I guess the oil interests have successfully gotten to Argonne Labs and influenced the GREET to be biased against batteries. I don't have time to dig deeper but I'm pretty sure there are some assumptions being made about batteries being full of toxic chemicals (which Li-ion and NiMH aren't) of forgetting that gasoline weight is a consumable while battery weight is a recycleable semi-durable material.
Also, why isn't Tesla on this list? I guess this game only allows the big guys to play.

· · 7 years ago

I don't get it either. In terms of "greenness", I find it hard to believe that a +/- 25% improvement in fuel economy would be outweighed by the presence of a NiMH battery pack. Over 100K miles, a 40 mpg car will burn 2500 gallons of gasoline, vs. 2000 gallons in a 50 mpg car. Does it "cost" the equivalent of 500 gallons of gas to manufacture one Prius battery pack? I *highly* doubt it. Can anyone recommend documents/studies that point to the energy cost and/or environmental impact of manufacturing NiMH and Li-ion batteries?

· Samie (not verified) · 7 years ago

"new GREET methodology, batteries are considered to have a greater environmental impact"

Ok I understand that but I wonder if GREET methodology considered transportation of natural gas through zillions of miles of pipeline that can disrupt migration patterns (or the zillions more pipeline needed to support a CNG transportation infrastructure), or the current extraction of natural gas, or compression factors, or leaky pipes, or the inefficiencies of storing it in a tank for "fuel".

Just saying, like other alternatives, natural gas is not an angel when considering all envr. factors....

· · 7 years ago

Hey Guys - I understand your doubts. At the same time, I know and respect the folks at ACEEE. I also know that they are doing everything possible to try to create a fact-based unbiased method for scoring greenness. They really don't have any axe to grind, except to try to be even-handed. I'm happy to serve as a liaison and get our questions answered about how the results were produced. Once again, I think the community can have an influence on an important stakeholder group. I'm not apologizing or protecting ACEEE. Let's have a frank conversation with them. Keep in mind that this is the very first year that plug-in cars are in the field.

· Mike__ (not verified) · 7 years ago

They can't even get the Prius' engine right - it's a 1.8L, not a 2.0L. Makes me wonder what other date was skewed in their analysis.....

· · 7 years ago

Apparently your ACEEE friends don't understand that garbage-in generally leads to garbage-out. It looks at face value like the falacy here is that the GREET standards from Argonne are the source of the problem.
We can expect this and many more efforts to get seemingly unbiased and credible sources to come out with this kind of nonesense now that EVs are starting to gain a foothold.
Up to the mid '90's, the mantra was that "EV technology wouldn't work".
In the early '2000's, after NiMH batteries came out, IGBTs improved drivetrain efficiency, and fast charging was developed to disprove the previous mantra, it changed to "there is no market for them"
Now, I guess the tact is that "they may work and people may think that they want them but they really aren't any better ecologically than oil or gas"
Sorry Brad but your friends, if they aren't actually shills themselves, are just naive fools being played as stooges for someone, most likely the incumbent ICE and oil industry.

· · 7 years ago

The Chevy Volt, dead last. Now who couldn't of seen that one coming? "ex-EV1 driver", I was also wondering why Telsa wasn't included in the test and the new electric Ford Focus. Do you think ACEEE was afraid that those two "totally green" cars would've drove the Volt right off the chart and into the back woods of some foreign country somewhere? And "Sami" those transporting pipes are mostly underground - out of sight, out of mind, out of all reports when you mention fossil fuel vehicles.

· · 7 years ago

Where's the CNG infrastructure? What's the full carbon footprint of CNG? If they are just counting the carbon in the gas itself, they are being disingenuous, or otherwise obscuring the full picture.


· Samie (not verified) · 7 years ago

Ok I'm a bit confused here
what exactly are they counting in their environmental factors or say "footprint".

Are we talking about post production?

Or do we including all inputs into the the manufacturing process of the vehicle?

Do we include the foot print of how the "fuel" is extracted, transported, & consumed?

Are there any university or EIA studies that confirm ACEEE’s variables or methodology?

Brad I am confused and a bit suspicious of this research. Not sure if proper scientific methods were done or if this was reviewed by an independent peer-reviewed journal. Maybe I'm wrong but another interview and explanation of methods would be great to clear up the confusion.

· · 7 years ago

I'm also not sure the ACEEE folks have factored in the latest EPA report on natural gas' upstream environmental footprint.

· LakeCountyHybrid (not verified) · 7 years ago

I am not sure why people find this suprising, this civic has been winning this over the prius for years, so why all of a sudden doubt the numbers, the way I understand the calculation is that it takes all factors of pre production, manufacturing, post production and the car itself into consideration. So a car made in a greener factory is going to do better than say the Chevy Volt which is probably made in a refitted and inefficient factory. I for one want to know the true footprint of a car, not just the car itself. If all you want is a ranking of car efficiency, anyone can give you that, its all over the internet, just pick you way you want to judge efficiency, but in this case they are looking at an over arching view of the whole process.

· · 7 years ago

I, for one want to know the footprint of the technology when a new technology is introduced. It isn't fair to penalize a new technology that has incredible potential, just because it took $1Billion to develop the first one.
It's like writing off a baby because they aren't of any use to anyone.
I will admit that the study evaluates current vehicles, and doesn't claim to look at a technology's potential. I do, however, question their battery assumptions.
I, however, don't care about the Civic GX, I'm most upset at the gas guzzling Smart.

· · 7 years ago

Indeed, I don't think we should be too quick to knock CNG. After all, at least here in California, a great deal of our electricity comes from natural gas. Burning CNG in an ICE might not be totally efficient, but neither is transmitting electricity from gas-fired power plants. I also like the fact that CNG is largely a domestic fuel. The biggest downsides of a CNG vehicle are that you are still locked into a fossil fuel, which would not be the case if you own an EV and install solar PV, and the limited fueling infrastructure.

· · 7 years ago

A regular customer of my restaurant has a Smart Fourtwo. He's always asking me about the MINI-E and say's his next car will be an EV. While he generally likes it he does say he's disappointed with the Smart's fuel economy and that he gets about 31mpg on average. To me, that's just way short of what I would expect if I was driving a car that small. It makes my MINI feel like a limo. (yes I've driven one). For me to even consider driving a tuna can like that I would want it to get 60+MPG.
I'll file this study with the others that really can't get a true grasp on all the variables, which I understand is very difficult to do. Like if a volt or LEAF owner has a solar PV array. Maybe they are really trying to consider as much as possible, but I see it as more of a guideline than a real hard list.

· · 7 years ago

@Tom Moloughney,
I see it as more of a guideline than a real hard list.
Unfortunately, policy makers won't see it as such. They'll see this as a credible study from a credible organization that clearly states that gas guzzlers such as the Smart, the Prius, Fiesta, Cruze, HCH, Elantra, Cooper, and Yaris are more ecological than the Volt.
Of course, I have no love for policy makers because of their inability to handle technical issues. This is exactly the kind of weapon that is used to manipulate policy makers to rule in favor of those with strong financial backing.

· · 7 years ago

It is not difficult to findout how they are calculating things. I've not checked out their methodology in detail - so I'm not going to comment much now. One thing ofcourse is, EVs are really for the future i.e. as the grid gets cleaner so will EVs. Fossil cars OTOH will get dirtier seince we expect fossil fuel production to get dirtier. Also we don't have a national grid - we have regional grids. So, using a national grid average isn't very useful, esp. given the strong coal lobby in some states. In the west grid is much cleaner - and in NW even more so. A lot of us get 100% renewable electricity - that will make Leaf as green as it can get for now.

"How we rate the vehicles We analyze automakers' test results for fuel economy and emissions as reported to the U.S. Environmental Protection Agency and the California Air Resources Board, along with other specifications reported by automakers. We estimate pollution from vehicle manufacturing, from the production and distribution of fuel and from vehicle tailpipes. We count air pollution, such as fine particles, nitrogen oxides, hydrocarbons and other pollutants according to the health problems caused by each pollutant. We then factor in greenhouse gases (such as carbon dioxide) and combine the emissions estimates into a Green Score that runs on a scale from 0 to 100. The top vehicles this year score a 57, the average is 32 and the worst gas-guzzlers score around 16."

· · 7 years ago

I don't have time to dig into their ineptitude. If you have, can you explain the following:
1) how do they decide the proportion of EV -vs- ICE miles a Volt will go?
2) how do they come up with the amount of ecological damage that is caused by battery manufacturing?
3) What grid mix to they consider when rating EVs?
4) What do they consider regarding natural gas production ecological damage?

I'd also like to add that while the grid may be regional, automobile mass-production is fairly national in scope since the auto dealers need to be able to sell many cars in order to make them affordable. This means that one can and IMHO should look at the grid average and future average when it comes to deciding what automobile technologies to promote.
Irregardless, I'd prefer to burn US Coal, gas, and Uranium than imported oil any day but the grid is even better than that and getting better.

· · 7 years ago

@ex - I have a few of those answers.
1) To determine the amount of EV vs. ICE, they used documentation apparently available from DOT, EPA and others, which shows specific real-life driving patterns of American drivers. It's the same thing that Mike Duoba from Argonne told me last year, with regard to testing for PHEVs:

"Results for plug-in hybrids with varying degrees of all-electric range and battery sizes are weighted based on large Department of Transportation surveys of average U.S. driving patterns."

So, it's not typical driving patterns for Volt or EV drives, but widespread patterns across the entire driving population as the filter to produce 2/3 for EV and 1/3 Gas for the ACEEE results.

2) I believe that battery manufacturing impacts come right from GREET 2.7. At least, that's my understanding.

3) ACEEE uses national average for grid. And they acknowledged that the LEAF (and presumably the Volt) will do much better in the Pacific Northwest or other areas with greener grids. ACEEE has an interest in developing an interactive tool to eval greenness based on location, for the overall 2011 rankings, they used the national average.

4) Don't know about gas production damage.

I'll let this thread percolate for another day or two, and go back to ACEEE with questions. My understanding is that they welcome the challenging questions--all in an effort to get the best answers to consumers.

· Richard Poor (not verified) · 7 years ago

Amen to most of the points already made! Who says a Volt driver will use up all or most of the electric every day? 100 MPG to the grocery matters more for most drivers than 35 MPG on the semi-annual, 600 mile trip.

Not only a footprint from natural gas extraction and transportation, what about compression? And again and again, where is the mention that an EV or PHEV charged with PV further reduces pollution footprint at less cost than $2.50/gallon at the retail pump!

· · 7 years ago

Brad, I would like you to get some clarification about how, according to the Bureau of Transportation Statistics 78% of Americans drive less than 40 miles per day. Hypothetically then, if any of these are volt owners, they will never use gas, or extremely little. They remaining 22% would have to drive an extraordinary amount of miles above 40 per day to raise the entire average up to 2/3 all electric & 1/3 gasoline.

This seems to go against the "two-thirds EV and one-third gas" approach used by the Society of Automotive Engineers and the Environmental Protection Agency.
Something's not in sync.

· · 7 years ago

Tom, see the link below. The data is from 2003 so it is pretty outdated. 78% is for "home to work" round trip. It is NOT for the entire day. Also, Chevy Volt is rated for 35 miles range (not 40). Therefore, 2/3 electric and 1/3 gasoline is sound.

· · 7 years ago

This is not encouraging. I just clicked through to the ACEEE's "exacting methodology" page and it's still thinks diesel engines are back in 2006. All the new ones are Tier 2, Bin 5 ULEV engines.

· · 7 years ago

There's another very disturbing data point in the chart. I'm not sure how they get that the Nissan Leaf gets 3.15/2.72 mi/kWhr but I'm pretty sure that if I drove a Leaf the same way that driving a Prius would give me 51/48 mpg, I'd get at least 4 mi/kWhr, even with full A/C blaring. I'd probably closer to 4.5 or 5 mi/kWhr. Does anyone have the official EPA mi/kWhr from the Leaf sticker (even though it is also suspect in the current political climate)?
The closer I look at this report, the more it stinks.

· Charles (not verified) · 7 years ago

ex-EV1 driver, the website has all the information you need to get to the 3.15/2.72 data points. The numbers look correct to me (OK, I rounded up to 3.15/2.73).

The EPA lists my car at 22/30. The lowest I have gotten at any fill up is 24. The lowest when buying at least 10 gallons has been 26. If I got only 30 on the highway I would think something was very wrong with my car. The lowest highway figure I have ever recorded was 32. Typical is 34 and I have gotten 37 on consecutive tanks. So at least for some cars with some drivers the EPA way under estimates.

· · 7 years ago

@ex-EV1 driver · As to Leaf's EPA ratings, there are some problems.

EPA did their normal city/highway tests. Then just like they do for ICE, used a 30% fudge factor to reduce Leaf's efficiency (and range). Preliminary results from Leaf owners shows that even with predominantly highway driving (SoCal etc) people are getting more than 80 miles of range.

Anyway, here is all the info on Volt & Leaf EPA tests. Someone actually did a FOIA request to get the information.

· Samie (not verified) · 7 years ago

Brad, your friends at ACEEE, have a broken link to the technical report

As I see it many assumptions have been placed for missing variables.

Ex-EV driver is 100% right about law markers seeing this as an official report even if this is a guideline and not true research. This doesn't seem important to the common Joe but using scientific logic/method and review by independent professional peers has a huge impact on overall accuracy of a study, thus reducing misconstrued data from being used for political gain. From personal experience, studies like this one with even the slightest alteration of variables could create misnomers in the results. I don't have time to look at the report now but I will to do so tomorrow night.

· · 7 years ago

@Charles and EVNow,
Thanks for digging these up. I guess I now know where the offending information came from but I still don't know who the rat in that silo is.
I can't wait for a Consumer Reports and other independent labs to start testing the Leaf. I'm sure we won't see horrible performance numbers like the EPA test has. I can get that kind of performance from the Tesla at 75 to 80 mph (not that I really ever drive that fast ,-) and I'm sure the Leaf is more aerodynamic than the Tesla Roadster so it should be better, despite the extra weight.

· Priusmaniac (not verified) · 7 years ago

There are basic assumptions done that are just not correct.

Battery weight count more. In fact it is rather the contrary since batteries are heavily recycled.

Natural gas. This is a standard brainwashing since there is no such thing like natural gas. You have to drill hard in special places to extract it from deep underground. In more it is dirty fossil gas that has nothing to do with biogas.

Clean diesel. This is another brainwashing since diesel is a fossil fuel, there can never be something like a clean diesel. The only thing that could be is clean biodiesel but that is already very different. In more these engines usually emit scores of particulate matter that are emitted free in the air. Some rare vehicles have filters but these only retain the largest particles which happen to be the less harmful. The only way to eliminate them all is by having an oxidative post treatment on it, but this kind of device is even rarer then filters.

Global electricity. That is also something that is not correct since you are not responsible for what the utility is delivering. If you do your part of driving EV as much as possible, it is the utility part to provide fossil free electricity. This also doesn’t tell that most EV drivers have also solar roofs.

If you take all this unto account and also consider how much persons can be transported, you are back at the following much more expectable and logical result:

Nissan Leaf
Tesla roadster
Chevrolet Volt
Toyota Prius
Honda Civic Hybrid
Honda Insight
Honda Civic GX
Ford Fiesta SFE
Chevrolet Cruze Eco
Hyundai Elantra
Mini Cooper
Toyota Yaris

Since the Smart Fortwo only sits two it gets off the list while the Tesla remains because it is pure EV.

· · 7 years ago

I agree with your list. Perhaps the (beloved) Tesla and the Volt could be interchanged but that's just nit-picking. I suspect that the Volt may have better aerodynamics than the Roadster and it's 4-seat utility should also be taken into account. It's price makes it accessible to the masses - hence a larger direct benefit to the planet. . . . or maybe the attention that the flashy Tesla draws to the feasibility of EVs offsets its lesser utility and volume :-)
Somehow, the anti-EV biases continue to need to get squashed. Fortunately, the Leaf and Volt are here, now, in large quantities so real data can be collected.

· George Parrott (not verified) · 7 years ago

My LEAF arrives in the next couple of days, and so far in the 1500+ miles I have recorded on our new Volt, we have a lifetime fuel use of 12.4 gallons. Further, since our house is fully solar panel fitted with enough capacity to totally offset ALL of our household electricity use AND still contribute 1200kW to the grid last year, even charging both EV cars we will have a "net zero" annual electricity use bill.

To me, that is about as green as it will get for local commuting and the option for worry-free infrequent road trips.

As an ex-Prius owner, I can assure all that the annual fuel consumption on our Prius of over 300 gallons (we kept VERY complete records of every fill-up) and emissions were massively greater than what we will be seeing with the Volt, since 90+% of all the Volt "trips" will be totally EV functioning.

· Jason (not verified) · 7 years ago

I guess I'm just confused about why all electric vehicles like the Leaf are even in the running. I'm sorry folks, we can split hairs all day long but the fact is, 50% of all electricity in this country comes from coal. In some states, like Missouri where I live, it's 85%. How does this make all electric plug-ins environmentally friendly or energy efficient? It would be better to stick with gasoline and diesel than to switch to coal for transportation. And if anyone believes the electric companies are going to kiss the billions they've already invested in coal power plants good bye so they can build wind turbines and solar panels, you're fooling yourself. For better or worse, the best alternative fuel is natural gas. It's cleaner, cheaper and an abundant American resource. It's not perfect, but no other alternative fuel can match its advantages any way you look at it.

· · 7 years ago

@Jason, If you are "confused about why all electric vehicles like the Leaf are even in the running" you need to do a bit more research. If you did, you would find that some of your assumptions have been refuted repeatedly here and elsewhere.

You say that "it would be better to stick with gasoline and diesel than to switch to coal for transportation." Really?

• Even if an EV were powered by 100% coal generated electricity its equivalent carbon "mileage" would be about the same as a Prius. And what about the many parts of the country have greener grids than all coal?

• The national grid can be expected to get "greener" over time. It is easier to clean up a handful of power plants than millions of oil burning cars.

• Most of the cars will be charging at night when the power grid is generating excess power (as I understand it, it is difficult to spin down large scale coal and nuclear plants).

And so forth. Better to power a car with American coal than imported oil, in my view.

Since you are an advocate of natural gas, consider that it is more practical to use that gas to generate electricity than to compress it to use directly in an ICE. (BTW, one of the advantages of an EV versus an ICE car, even when powered by CNG, is greatly reduced maintenance due to fewer moving parts. Had you considered that?) With electricity, every garage has a fueling station. No need for expensive (electrically powered, inefficient) NG compressors.

Even in your mostly coal-powered state, you could, if you wish, install solar panels and charge an EV that way. Powering a car with sunshine is a whole lot cleaner than natural gas or any other fossil fuel.

· · 7 years ago

And then there's folks like me who read about ACEEEs green ratings and decide - who cares? Maybe the most green car is the Civic GX. It is still more expensive than other alternatives, it still has a smaller trunk and a shorter driving range. Then there is the debate over just how bad greenhouse gasses are. Some say water vapor (which comes out the exhaust of the Civic GX and not the Leaf) is actually a greater greenhouse gas than CO2. Bottom line for me is what vehicle provides me the best value (most efficient and most reliable including comfort and safety with minimal polution) for transporting me and my stuff. Civic GX. Prius, Leaf? - maybe - Smart for 2? NOT!

· Dion (not verified) · 7 years ago

the Volt is economical, stuff what emissions they throw out in the open. Its much more fuel efficient than the conventional car...

· Max Reid (not verified) · 7 years ago

All electricity in the USA is not generated from Coal as some skeptics of EVs talk.

Share of sources as of 2009.
Coal : 45 %
Natgas : 23%
Nuclear : 20%
Hydro : 7%
Renewables : 4%
Petroleum : 1%

In 2010, Petroleum's share is even less. Best of all the electricity is 99% domestic whereas Oil is 65% foreign.

· George Parrott (not verified) · 7 years ago

I posted this elsewhere, but the glaring concern, despite Brad's affirmation that "he knows the people in the ACEE," is WHO FUNDS THIS GROUP?

I suspect if we follow the $$$ we will see more about what and why the biases are where they are. (Since the ordering presented is simply borderline nonrational, IMHO of course).

· · 7 years ago

Let's not get conspiratorial. Instead, let's focus on the rational points where ACEEE's methodology might have faults. The lines of communication are open, and we should try to point out any weaknesses and where things could be approved.

Does everybody agree that it's possible to establish a solid methodology for comparing the greenness of an EV vs. PHEV vs. Hybrid vs. Diesel vs. pure ICE...etc.

What does a sober, rational, careful, fair and light-tight methodology look like? If not GREET 2.7, then what do you use? If not CARB certifications, then what do you hang your hat on?

Let's help instead of pointing fingers.

· Max Reid (not verified) · 7 years ago

Brad Berman

Thanks for publishing a very useful article.
Just like Shale gas is not as clean as conventional Natgas from gas fields, the current Coal is also not as clean as the Coal of the past.

I met a Mechanical Engineer in a train who works in a company which designs scrubbers for the power plants. He said that now a days, the Coal has lot of sulphur and other particles which involve high maintenance. But the good thing is still Coal is a domestic commodity and our tax dollars are not spent on wars and terror fights.

Another important fact is that in the last 2 years the price of Solar panels have gone down by 50% because of dumping from China. As the fossil fuel prices go up and the price of Solar & Wind goes down, there will soon be a parity and from that point, the renewables will accelerate giving the greener color for Plugins & EVs.

· · 7 years ago

@Brad Berman · What does a sober, rational, careful, fair and light-tight methodology look like?

Look for a study called "Potential Impacts of Plug-in Hybrid Electric Vehicles on Regional Power Generation" by Stanton W. Hadley. That is a good start - they model marginal emissions because of plugins by region and time of charging.

Also I think all studies should include scenarios of 100% renewable charging.

I've not looked at their well-to-wheel numbers for fossil fuels. But, being "sustainable" to me is the essence of being "green". They need to think carefully about this - otherwise just changes their title from green cars to cars with least carbon footprint.

· · 7 years ago

@George Parrott,
It's a pretty big conspiracy, if you want to go there:

All the usual suspects--and then some. Except the auto and oil companies.

· · 7 years ago

@Michael Coates,
Are you really saying it you think it aceee is a big conspiracy?!? Or are you being sarcastic? Do you really think all those different foundations, universities, government agencies, labratories, private companies are somehow all working together to deceive us?!? At worst, some of their statistics and calculation methods and some data may be slightly outdated. I also think the main discussion of this thread questioning their methods and assumptions is excellent. If aceee has its own agenda it may be able to deceive some of its sponsors. But for goodness sakes DOW Chemical on the one hand and Sierra Club on the other working on a conspiracy?!? Together!?! @GeorgeParrott are you getting this?
Maybe aceee is not the right shade of green for some of us and it is certainly good to challenge their assumptions, but a conspiracy?!? Give me a break...

· · 7 years ago

Guess I needed add an emoticon. Then again, the Gas Technology Institute and a load of natural gas utilities are contributors. Sorry, couldn't resist. ;^>

· · 7 years ago

Its always a good idea to follow the money trail. I took a quick look at this for ACEEE as soon as Brad broke the story. There aren't any smoking guns there. Additionally, most of the date comes from the EPA, Argonne labs' GREET, and other studies. These are where the questionable numbers seem to come from. I'm interested in finding out how they justify their penalties for batteries and low mi/kWhr numbers.

· Anonymous (not verified) · 7 years ago

I agree with the dissenters in regards to these results. I especially question CNG cars as being the greenest. it takes a lot of energy to get the gas , transport it, store it and compress it.
PS EV's are the cleanest cars period. This crap about coal burning plants, is becoming a huge farce. We can and know how to build or convert old coal burning plants to very efficient plants, much like high efficiency furnaces in our homes. The problem is. Electric corp. do not want to invest in the wellness of our communities.

· Max Reid (not verified) · 7 years ago

Lets not argue as what is good between Natgas Vehicle and Plugin / EV which gets 1/2 power from Coal.

Since the Oil prices are rising with latest gas prices @ 3.14, its better to go either way : NGV or Plugin. As long as we can reduce our oil consumption more money will be within the country and it will help in economic recovery.

The latest trend in Power industry is the booming Wood fired power plants. Either wood is used solely or its is used along side Coal in Coal fired power plants. These wood are renewable that some trees are grown, then they are cut and grown again in the same land.

Across UK & Europe, many wood fired power plants as large as 300 MW are being built. The other advantage of these is that the waste heat can also be used for space or water heating in the nearby homes & factories. As the Chinese have started importing Coal, the prices are increasing which will move the World towards all sorts of renewables.

· · 7 years ago

Looking at the funding sources, I think ACEEE has enough credibility among the various influencers in the environmental area. So, it is important for any of us who think the methodology is faulty is to give concrete examples, if not suggest alternatives, so that ACEEE can address them.

· Pierre (not verified) · 7 years ago


I am baffled that, according to AEEE, the Honda Insight is classified as Bin 3 only.
However, according to Honda press release, 2011 Insight is classified as ULEV/AT-PZEV, which is the same as the Toyota Prius.

· Carl (not verified) · 7 years ago

I am an atmospheric scientist and have worked in various aspects of air quality for over 25 years. I agree with Brad Berman, the methodology used by ACEEE is probably as sound as you can get since they use life-cycle emissions based on the GREET model which was developed by a U.S. government entity - Argonne National Laboratory - which would be least likely to have any vested interest in any particular technology.

I would like to have more detail on the methodology used by ACEEE in their "green car" determination, e.g., what weighting factors they used for each emission parameter like CO2, NOx, SOx, etc., as well as the formula used to derive the score.

At any rate, this beats a lot of the other "green car" evaluations which use the "Bin" a specific car model hits as their only criterion.

· Job001 (not verified) · 7 years ago

Natural gas has twice the hydrogen to carbon ratio of gasoline, explaining a significant boost in Green rating for the Honda Civic GX. It's funny to see the reaction of "True believers" when challenged. Natural gas also doesn't emit a lot of CO2 as crude does when being refinery processed into gasoline.

· Job001 (not verified) · 7 years ago

When a great design of a plug in Hybrid GX can be manufactured at competitive cost, it will undoubtedly take the lead.

· · 7 years ago

The only problems I see with natural gas are:
1) not renewable (although if someone finds a viable way of getting hydrogen from a renewable source you could burn hydrogen in a natural gas engine)
2) its more difficult to transfer a gas than a liquid
3) It can be tough to protect the CNG gas tank so it isn't too dangerous in an accident
4) It can be hard to carry enough CNG to get more than ~200 miles of range without either a large gas tank (good bye trunk) or under very
high pressure (see #3) above)

The CNG hybrid you mention will help with #3) and #4) above.

Of course, Honda will have to do a much better job at vehicle integration since they can't take up the trunk with both a CNG tank and batteries as they do now. There won't be any trunk left at all.

I, for one, have no quarrel with it's emissions characteristics or the fact that most of our natural gas comes from US sources.

· RICHARD JOASH TAN (not verified) · 7 years ago

I believe that the Volt Should be the greenest car FOR ETERNITY!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

· · 7 years ago

hmm, I just looked at and found that they list the Leaf as 3.2/3.7 mi/kWhr. I'm not seeing where ACEEE got 3.15/2.72 mi/kWhr. I guess that may mean that the EPA ratings aren't the source of the bias.
It makes no sense that the Volt's positionchange was caused simply because of the engine size but the fuel economy stayed the same. Who cares what size the engine is?
I also can't see how the engine size should affect a car's 'greenness'. It sounds like if a car got 100 mpg, but had a 6.3 liter V-8, it would be rated lower than a car that got less mileage but had a 2 cylinder engine.
This study really stinks.
These guys seem like manipulated morons at best, evil propagandists at worst.

· · 7 years ago

Your table lists the Volt ICE as 1 liter when it is 1.4 Liter. Does the source document have the same error ?

Since I am not a Volt (or LEAF, for that matter) fanatic I do not have to fall over myself hating this study, but I do have two critiques to add: First, using national grid mix is really, really stupid. Fuel source to cover the additional demands of EV are what matter. Second, no two people will ever agree on the weighted averages of different pollutants, in part because of local considerations and more generally due to difficulties projecting costs of climate change.

Other criticism comes to mind, like using average driving patterns to extrapolate EV grid use (as if owners are a random sample!), but my first paragraph bugs me the most.

· Anonymous (not verified) · 7 years ago

As with others, this appears to be a garbage in, garbage out rating system.
They did not know the engine size of the Prius, and if the above table is correct, they still do not know the engine size of the Volt (1.4 liter versus 1.0 liter.)

A green car is simply a car that strives not to harm the environment. If you think man-made CO2 emissions harm the environment you come up with a different rating than you would using other emission standards.

Intuitively, most of us would conclude electrics like the Leaf and the Tesla would be the greenest, followed by plug-in hybrids like the Volt and the Prius PHV.

And most of us are willing to be educated. What factors about lithium battery production are used to down grade the EV scores?

By mid-2012 we will have better choices and hopefully better analysis of environmental impact.

· · 7 years ago

CNG gets us off of oil IMMEDIATELY.

I only hope Honda combines it w/Li ion hybrid tech, even if it is their IMA, to push the GX that much further out ahead of the competition.

Go Honda!

· · 7 years ago

As a suggestion for improvement, the rating should have class of vehicle. E.g: sub-compact, compact, mid-size, etc..

· · 7 years ago

@John K.
I, personally believe that the benefit plug-ins have of being able to run off of nearly any energy source (including Natural Gas) more efficiently through electrical power is essential for our viable future transportation using current technology. I don't believe we can afford to wait for any breakthroughs.
Coupling the plug with a redundant power source that can be carried onboard in greater quantities is fine as well, as long as most of the driving comes from electricity. Natural Gas, Diesel, and Gasoline are all fine as the backups.
I do see relative merits between these but I am not opposed to any of them. My preferences and reasoning are (in order of preference) as follows:
1) Diesel Engine - Most efficient, most flexible fuel sources (petro-diesel fuel, bio-diesel, waste-vegetable oil, natural gas, propane, blends (kerosene, gasoline, with other things)
2) Gasoline - its what's out there today. It has a list of bad-things but since its use would be minimal, not essential, and inconvenient, I still put it slightly ahead of Natural Gas but welcome others to work to solve the Natural Gas issues.
3) Natural Gas (or propane) - its nice and clean burning but is hard to transfer, transport, and store. Its infrastructure is not as widespread as Gasoline

· JRP3 (not verified) · 7 years ago

Glad to see some questions being raised about this study. They seem to weight the impact of building a battery pack rather heavily but is it really worse than building hundreds of pounds of complex ICE, multispeed transmission, exhaust system and catalyst, etc? As for the cleanliness of CNG, ask the people who's wells have been contaminated from poor fracking techniques, and how about the rather frequent NG explosions that seem to happen, what are the emissions from those? Just Google "natural gas explosion" and watch all the videos. I'm quite happy not to have this stuff plumbed into my house, let alone my car. Use it in highly controlled generating plants if we must.

· · 7 years ago

@JRP3, Oh come on. Natural gas has been used safely in houses for many decades. You can find horror stories about any kind of fuel: how about the danger of driving around with a tank of explosive gasoline, which most of us seem to take for granted? Or electrocution when using electricity?

I switched my house from propane to NG last summer to take advantage of the convenience and substantially lower prices. Propane is more dangerous because it is heavier than air and accumulates if there is a leak, whereas NG disperses quickly.

As you mentioned, the real downside of natural gas is the environmental damage of the drilling process. My state is a major gas producer so I get to see it for myself. On balance I think the domestic energy production is worth it, versus importing oil, but there are areas that should be left undrilled.

· · 7 years ago


As your Regulators nitpick and you guys navel gaze, our North American Auto Industry slowly sinks into the western sky. Wake to the Oil Boys (tell 'em to let go) because China, Carlos (Japan/France) and Korea (their batteries) are going to eat our lunch!!

· JRP3 (not verified) · 7 years ago

Seriously, google natural gas explosions and see how many and how often. I think there have been three major explosions in the last 10 days or so. I'm not making this up, there are millions of miles of deteriorating pipelines under our houses that seem to be blowing up with alarming frequency. Gasoline and electricity to not blow up neighborhoods.

· · 7 years ago

@JRP3, And how many of those "millions of miles of deteriorating pipelines under our houses" DIDN'T blow up "in the last 10 days or so"? You are taking rare events and making unwarranted extrapolations, but ignoring the tens of millions of houses using natural gas every day that don't blow up. Far more people die every "10 days or so" from drunk or distracted — cell phone using — drivers. Do you hide at home afraid to drive?

The point I am trying to make is that we have a tendency to extrapolate risk from rare events and ignore risk from routine events. The classic example is the attention a plane crash gets when more people die every day on our roads. The statistical risk per passenger mile in an airliner is substantially less than that in a car yet people, myself included, tend to worry more about flying than driving.

The idea that a microscopic percentage of natural gas users who experience an explosion or fire means that natural gas isn't safe to use in houses is illogical. It is one's mind trying to see patterns in rare events.

If you can't accept that, fine. My purpose in challenging your assertion was to prevent it from being credulously accepted by others.

· JRP3 (not verified) · 7 years ago

A quick Google shows three explosions in the last 10 days. People can apply their own metrics regarding risk assessment. I see an increasing problem with aging pipelines, which may be statistically insignificant but clearly points out the potential danger of NG that electricity does not have. That danger should be considered when putting an explosive fuel in moving vehicles that have to be connected and disconnected frequently when fueling with tightly sealed connections. There are many failure points in the whole CNG vehicle infrastructure, from the pipelines all the way to the vehicle.
Finally, using NG in centrally located generating plants to power EV's is much less complex, more easily managed, safer, and more efficient than burning it in inefficient ICE vehicles. Since the LEAF and GX basically tied at 54 points in this study using grid average the LEAF would obviously beat the GX if plugged into a grid that used NG to replace coal. We should use NG in the most efficient and safest manner possible.

· · 7 years ago

@JRP3: With anything, I figure that if the risks are statistically insignificant, then it's not worth worrying about. On the other hand, I do need to endeavor not to slam into a tree while backcountry skiing, or crash while driving on our icy roads. Yes, I find natural gas very useful for cooking, drying our clothing, and heating (when not using our pellet stove).

As for fueling cars, it still makes sense to use natural gas if you need more range than a current EV can provide and you have access to CNG fueling infrastructure. As has been mentioned, the Civic GX has a range of over 200 miles per fill-up. That said, EVs are clearly more efficient and it does help that electrical power is ubiquitous. (Currently, I do have a "pending" LEAF order.)

· Alan (not verified) · 7 years ago

This list is a very specific list regarding emissions - it does not cover fuels savings etc. All diesel cars are emitted even those that get 40+mpg. In the real world ... really ... The Honda Civic NG is NOT #1 with regards to anything else.

Efficiency vs Emissions - not the same thing here! - I could have a direct injected hydrogen driven ICE with hydrogen produced from solar and wind power - it would be the greenest car on earth ... but would not win the efficiency race!

· JRP3 (not verified) · 7 years ago

I find electricity quite useful for all the things you mentioned, and much safer. Regardless of the statistical safety record of home NG use one can reasonably expect more problems using it in vehicles that have connections that must be repeatedly made. All your NG appliances have permanent connections, your CNG vehicle does not. You get a small leak in your connector as it fills overnight you might wake up to a big surprise.
Real world numbers for the Civic GX shows between 150-180 miles of range, less than a Tesla roadster, with far fewer fueling options. CNG vehicles are a wasteful application of the potential energy in NG. If you really need range get a hybrid for the next few years until more EV's are available with greater range than NG vehicles. Don't invest in an expensive infrastructure build out for a temporary technology that wastes a large portion of the fuel.

· · 7 years ago

@JRP3, I have to agree with you that the best use of NG for transportation purposes is to fuel power plants and use those to charge EVs.

My hope is that in a few years we will get EVs with sufficient range and enough fast charging infrastructure that PHEVs will be unnecessary for most purposes, so the question of what kind of range extender engine to use will become moot. In my case, just keeping my current ICE car as my backup for infrequent long distance trips is more efficient than buying a PHEV as a second car.

· Bill (not verified) · 7 years ago

ex-EV1 driver wrote: "3) It can be tough to protect the CNG gas tank so it isn't too dangerous in an accident
4) It can be hard to carry enough CNG to get more than ~200 miles of range without either a large gas tank (good bye trunk) or under very
high pressure"
First of all, I have a 2000 Honda GX and it's pretty obvious to me that you haven't done your research on cng tanks. The GX tank is MUCH safer than a gasoline tank. It can take a head-on collision (someone ramming it from behind) up to 100 mph and still pass the tests for integrity. Try that with a gasoline tank and see what happens. It can take 6 point-blank .45 magnums and still not explode or degrade the tank. It can withstand a fire (Honda added a NASA 'fire insulator'/blanket around the tank) because if it reaches a certain temp, it vents the gas. As far as range and using up the trunk, I added my extra tank to the back seat, so I still have my trunk AND now I have a 500 mile range. My fuel only costs $1.79/gge. I'm selling it to obtain a LEAF because I want to stop using our natural resources. I'll be charging my LEAF with our PVs during the DAY off-peak times.

· · 7 years ago

I'd say you pretty well confirm exactly what I said about CNG. It's hard to store. You had to give up your trunk and back seat to store 500 miles worth of fuel in it and they had to go to a lot of work to make it safe. Those .44 magnum bulletproof tanks are neither light or cheap.

· · 7 years ago

Here are the changes to the old methodology ACEEE is using :

Interesting notes :
- Vehicle lifecycle emissions is based on GREET 2.7. Unfortunately that doesn't include either PHEV, nor BEV. So, ACEEE assumed PHEV is like HEV and BEV is like a Fuel Cell vehilce !!!!!
- They assume all batteries are NiMH. They don't even have any figures for Li Ion batteries.
- They used a "utility" factor to figure out EV/CS modes of PHEVs. Unfortuntely they don't tell us what UF they actaully used in calculation. So, we don't know how representative the figure is.

Now I need to read the original 2004 document that gives the methodology in full to figure out what they are doing about the upstream emission of NG/Oil. Atleast they don't talk about any changes in that methodology or "costs" associated with it.

· · 7 years ago

Excellent smoking gun. I knew there was something very wrong with the GREET information they were using but haven't had a chance to dig it out.

· Michael (not verified) · 7 years ago

@ John K.

"CNG gets us off of oil IMMEDIATELY."

Exactly. The U.S. has huge natural gas reserves. The problem with natural gas, is prices are controlled by public utility commissions, who as far as I am concerned, are communists. They want to ration it through steeply tiered pricing. While it may be less expensive that gasoline today, you are only one PUC vote away from rendering your economical natural gas car worthless. The price risk has eliminated natural gas cars for the public. I fear the same will be true for electric vehicles, unless you are lucky enough to have the sunshine, capital, and building structure for photovoltaic cells. Even that holds risk, because a PUC could eliminate net metering.

· Bill (not verified) · 7 years ago

Michael, if my EU decides to eliminate net metering, I will go OFF grid with a battery storage system. Battery storage will become much less expensive in a few years or so. I'm planning on going off grid anyway as soon as an inexpensive battery storage device comes on the market. I've heard that some LEAF owners are planning on using their battery packs to supply their homes.

· · 7 years ago

You have to consider the source here.... your talking about people who think CO2 is a pollutant.... you know the stuff you breath out that makes vegetation grow.

The Chevy Volt is getting 10 times the MPG and uses a battery that can be recycled .. unlike the NIMH battery used in the Prius.

Then you have to remember this is a government agency... nuf said.

· · 7 years ago

It's actually kind of a comfort to know that my gas-powered car isn't a terrible choice while I'm saving up to buy something greener.

· Seaplaneguy (not verified) · 7 years ago

The Volt efficiency at 75 mph is about 55-60% and City, only about 26% in electric drive only mode. This tells me that the electric motors are not doing better than 30%. This is NOT good. Electric motor have their "BSFC" curve just like a piston crank engine does. If someone got (like me) a motor to perform at 60% all the time, it would about double the city driving provided it got 90% brake the EPA hybrid hydraulic system does. The new standard is a car MUST get 2x in city over highway or it is not designed right. Moreover, with the grid at 33%, an electric car would use 3 times MORE real energy than my car at 60%. Checkmate on electric cars...for the next 100 years.

· · 7 years ago

^^ How did you decide that city driving is 26% efficient in city driving ? Hopefully not from the silly MPGe.

· · 7 years ago

I'm not sure where you're getting your numbers from. Can you clarify a bit? Also, I'm very curious how you are getting 60% efficiency out of a (presumably gasoline) motor. Most gasoline motors run less than 20% in normal driving so you're more than 3 times better.
I hope it's true but I'm very skeptical.

· · 7 years ago

I would say out of all of the cars on the list, the Chevrolet Cruze Eco would be the best value, considering it's size and the base price of only $19, 175.

· · 7 years ago

The Hyundai is the better value for the short-term, selfish minded. I believe it is cheaper and has a much better warranty.
Long term thinkers will see the value of supporting technology that has a sustainable future, not just cheaper cost today.
Additionally, buying a Hyunday won't support an obnoxious company that crushes EVs and then tries bait-and-switch to lure folks into their showrooms with the promise of an EV (Volt), then tries to push them to buy what that company really wants to sell.
I guess we now know for whom Michael works though.

· · 7 years ago

You may need to guess again.

EV1 is ancient history. It's time to let go, my friend.

Also I recommend buying a car, rather than leasing it if you want to hang onto it.

Why should people buy a car (Hyundai) from a country (South Korea) that will not allow ours to be imported? Their market is completely shut down.

· Kiki (not verified) · 6 years ago

Hello all-

I drive from GA to TN from home to work m-f. The commute one way is 83 miles. Currently I have a Chevy HHR and I have to fill up twice a week depending on how I drive, I am looking for the best Hybrid for me. Any suggestions? I was looking at the Nissan Altima then the Chevy then the Honda. I have read all of the conversation on this thread but I need it put in simple terms. Please provide me some simple feedback!

Thanks for your time and energy!

· RoyGBIF (not verified) · 6 years ago

The day is coming when choice of the car you drive will be gone. Electric vehicles stink. Where is all the energy coming from? Higher energy prices at home when you plug it in. Energy is not created nor destroyed yet Obama thinks a paper windmill can take the place of coal/gas. What a fool. He is walking through his Waterloo.... high unemployment, housing market collapsing, and the value of the dollar in freefall.

· · 6 years ago

@RoyGBIF: Huh? I think you have it backwards. We have been living the past 100 years without choice. Now with electric cars we finally have a choice!

We can decide for ourselves what fuel we want to use for our personal transportation. I choose 100% domestic electricity and I know every penny of what I spend on it goes to US workers, US companies and US utilities. I don't want 65 to 70 cents of every dollar I spend on gasoline to get shipped out of our country and economy, and have some of that money used to kill US soldiers that are deployed in the middle east. We are funding BOTH sides of the wars we fight just so we can keep the oil flowing freely and cheaply.

The electric cars you are reading about today were all in development way before the president was elected so you can drop the "it's Obama's fault" crying, it only makes you look foolish.

Don't worry, nobody is taking away your precious oil burner. You can continue to line the pockets of the the sultans and sheiks with your hard earned money, but they're not getting any more of mine. That's choice!

New to EVs? Start here

  1. Seven Things To Know About Buying a Plug-In Car
    A few simple tips before you visit the dealership.
  2. Incentives for Plug-in Hybrids and Electric Cars
    Take advantage of credits and rebates to reduce EV costs.
  3. Buying Your First Home EV Charger
    You'll want a home charger. Here's how to buy the right one.