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GM Expects Chevrolet Volt to Deliver 230 mpg in City Driving Based on EPA Draft Methodology

11 August 2009

Based on the analysis of development data (both dynamometer and road-test) using a draft federal fuel economy methodology for extended-range electric vehicles (EREV) under discussion by the Environmental Protection Agency (EPA), GM expects the Chevrolet Volt will achieve city fuel economy of at least 230 mpg US, given a single charge per day (as the methodology assumes).

Based on the same draft EPA methodology, the Volt would also deliver “triple-digit” combined cycle fuel economy along with combined cycle electricity consumption of 25 kWh/100 miles, according to GM. At the US average cost of electricity (approximately 11 cents per kWh), GM calculates that a typical Volt driver would pay about $2.75 for electricity to travel 100 miles, or less than three cents per mile.

From the data we’ve seen, many Chevy Volt drivers might be able to be in pure electric mode on a daily basis without having to use virtually any gas. EPA labels are a yardstick for customers to compare a vehicles’ fuel efficiency. So, a vehicle like the Volt that achieves a combined triple-digit fuel economy is a game-changer...The key to high-mileage performance is for a Volt driver to plug into the electric grid at least once each day.

—GM CEO Fritz Henderson

Both GM and EPA, which is supportive of GM’s exercise, point out that (a) the methodology is not finalized; (b) that the data is preliminary, development-level data; and that (c), the EPA hasn’t yet done the testing itself. Nevertheless, said Frank Weber, Global Vehicle Line Executive and Chief Engineer for the Volt:

The 230 city mpg number is a great indication of the capabilities of the Volt’s electric propulsion system and its ability to displace gasoline. Actual testing with production vehicles will occur next year closer to vehicle launch. However, we are very encouraged by this development, and we also think that it is important to continue to share our findings in real time, as we have with other aspects of the Volt’s development.

While the fuel economy (FE) for combustible fueled vehicles (such as gasoline, diesel, compressed natural gas, or an ethanol blend) can easily be expressed in mpg, and fuel economy for an all-electric vehicle can be expressed in miles per gallon of gasoline equivalent (mpge), the arrival of new technologies that can operate in all-electric mode, a conventional hybrid mode, or some combination of the two complicates the situation.

The EPA is revisiting the FE label provisions as they apply to those types of vehicles, and is working with automakers, the SAE, the State of California, the Department of Energy and others to address these issues. The EPA anticipates issuing guidance and/or a rule this year.

Broadly, the EPA is considering using two additional approaches to FE calculation and labelling: one for extended range electric vehicles, and one for PHEVs.

For the EREV category, EPA would include vehicles that can complete all the EPA required drive traces for the FTP, highway, US06, and SC03 without some assist from a combustion engine (either for propulsion or as a genset). For this type of vehicle (into which category the Volt falls), EPA notes that there are three possible modes of operation to consider for FE labeling: all-electric operation (charge depleting mode), hybrid operation (charge sustaining mode) and a combination of the first two.

  • For all-electric mode, FE would be expressed in miles per gallon equivalent (mpge) and/or kWh per 100 miles. Fuel consumption, FCEV, would be measured by SAEJ1634, without the C coefficient adjustment. Fuel consumption is adjusted via the 5-cycle, derived 5-cycle, or other appropriate method.
  • City and highway fuel economy when the vehicle is in hybrid operation (charge sustaining mode) would be calculated and displayed as done for hybrids now.
  • When the vehicle operates in a combination of modes, some electric-only and some conventional hybrid operation, the value could be displayed in mpg, but only when accompanied by the appropriate amount of kWh/100 miles consumed.

For plug-in vehicles that require some assist from the engine for propulsion or as a generator for the test cycles (i.e., a plug-in hybrid), EPA suggests two types of FE labeling:

  • When the vehicle is in an electric assist operation, fuel economy would be expressed in miles per gallon equivalent (mpge) that incorporates both the electrical and gasoline consumption into one city and one highway FE. Gasoline and electricity consumption while in blended mode would be measured as in SAEJ1711 (earlier post). In addition to mpge, FE could be displayed separately for each fuel for the electric assist portion of the label in kWh/100 miles.
  • City and highway fuel economy when the vehicle is in hybrid operation would be calculated as for hybrids now.

The Volt, which is scheduled to start production in late 2010 as a 2011 model, is expected to travel up to 40 miles on electricity from a single charge of its 16 kWh Li-ion battery pack and be able to extend its overall range to more than 300 miles with its flex-fuel-capable engine-generator. Tony Posawatz, Vehicle Line Director for the Volt, said that the Volt is delivering 40 miles all electric in both city and highway cycles.

“In the future, ‘mpg’ ultimately will be moot.”
—Tony Posawatz

According to US Department of Transportation data, nearly eight of 10 Americans commute fewer than 40 miles a day. A Volt driver’s actual gas-free mileage will vary depending on how far he or she travels and other factors, such as how much cargo or how many passengers they carry and how much the air conditioner or other accessories are used.

However, Posawatz notes that since the Volt results are based on a single charge per day—and that given the recharge time of 6-8 hours on a standard 110V outlet or half that on a 240V charger, the Volt has the potential to deliver better than 230 mpg performance if it can charge multiple times per day.

Along those lines, GM used a media event at the Plug-in 2009 conference to show a prototype home 240V charging unit, as well as a second, portable 110V unit that would be stored in a container in the vehicle. Both use the J1772 connector.


August 11, 2009 in Electric (Battery), Hybrids, Plug-ins | Permalink | Comments (66) | TrackBack (0)


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So the Volt is getting 5 miles per kWh in city and in highway driving according to GM testing, or 4 miles per kWh according to EPA combined test cycle.

Not too shabby.

I log my miles for tax purposes, when I looked at last years mileage, I would have bought about 2.5 gallons of gasoline a month. This car would be amazing, room for my clients, energy independence cool, fairly sporty for a green car, and incredibly cheap to operate. Time to buy a wind generator for the backyard...
If they could get the price down to $30,000 I might actually buy one. It is a $16,000 car, plus an $8,000 battery, plus the electric power steering, electric heat pump, etc. How did they get to $40,000? It seems like it would be a $32-34,000 car, unless the advertised price is including a battery pack replacement midlife of the car.

The 230 mpg is certainly going to benefit the marketing efforts of the Volt as something much greener than a Prius. The electric consumption of 25kWh per 100 miles is also very good when compared to other full electric vehicles that do not have to carry the weight of the range extender. Volt 0.25, BYD,E6 0.29, Roadster 0.22, Model S 0.26, iMiEV 0.2, Aptera 0.12.

The Volt will be a good car but it will be difficult for GM to compete with the 22k USD Prius that is in super high volume production with 50,000 units per months. They will need all the subsidies they can get.

The price of the Volt is probably inflated for GM to get the highest return on its investment at possible while it can. Once Ford & Chrysler start competing with cheaper models & the EV market gets very crowded like the SUV market did years ago, prices should come down. By that time GM should have a much cheaper version available...probably named something like the Watt.

There's already the IEC 62196 connector which allows a larger charging rate. See for example
The standard chosen should not be limited to only what the first generation of cars can use.

GM has commented on why they are having to price the Volt much higher than they expected.
Originally Lutz just did a back of the envelope thing and added the extra costs of the battery and motor to the standard car.
This is new technology though, and in practise they found that they were going to have to throw out a lot of the old parts, such as the transmission, and move from mechanical to electric.
On top of that they are going to have to amortise the cost across what is projected to be a fairly small-selling line.
For a hybrid you have all the complexity of an ICE car, and then put on top of that you have an electric car if you are going to a full plug-in hybrid, and then the cost of integrating the two.
'The amazing thing about a dancing bear...'
Pure electric cars, or fuel cell cars, are much simpler.

"combined cycle electricity consumption of 25 kWh/100 miles"
250 Watt-hour per mile would take 10kWh to make 40 miles EV range. Volt has 16kWh pack with 8kWh usable energy. In another word, you won't get 40 EV miles if you travel on the highway.

230 City MPG sounds impressive. We need to know the highway MPG. We know the "Triple digits" combined MPG so it should be 100+ combined MPG.

If we assume Volt gets 100 combined MPG and compare it to Prius 50 MPG, you are displacing 1,500 gallons over it's 150k miles life time. Volt's 150 combined MPG would displace 2,000 gallons.

Does 1,500 to 2,000 gallon displacement justify the $20k premium price tag?

Prius displaces 3,000 gallons compare to a 25 MPG car with it's 1.3kWh HV battery pack.

Well now we know what GM's 230 campaign refers to.



Be thankful that the Obama/Reid?Pelosi administration are STOPPING new electrical generation plants (especially the scary nuclear plants - which are carbon neutral). With Obama/Reid/Pelosi at the helm we'll soon have electricity prices high enough to make gas cheap in comparison!!! And rolling brownouts... TOO BAD! You should WALK of BIKE wherever you go.



Have you considered the purchase of a BYD F6-DM PHEV or a 2010/11 Hyundai Sonata PHEV?

Both will sell under $30K and as low as $25K for The BYD F6-DM. If you have an oldy to trade in + incentives you may even get a deal for around $20K.

Worldwide competition will force Volt's price down in 2 to 3 years unless the USD is devalued by 30% to 50% or Asian currencies are revalued upwards by 30% to 50% or a bit of both....


Since I already have a Prius, a small EV is better for me as a second car. IQ or Smart size EV with 50-100 miles range would be ideal. This combination should cost less than the Volt.

Let's don't forget that, as I understand, a tax rebate of $7,500, can be applied toward a purchase of a plug-in hybrid. Which should bring the price of the Volt down significantly.

In such case, considering the savings from the very limited gas, oil, brake pads and rotors, and other lower maintenance which hybrids and electrics generate, owning a Volt might make economic sense.

Let's don't forget that if one drives around 15000 miles a year his spending on gas alone is around $2000. If the lifetime of your car is 10 years this will make it $20000.

To Ziv,

You said that green cars are not sporty. Well, purely electric cars are actually very sporty as electric engines are much more efficient compared to ICE. They also have a lot of torque. All of this makes them very responsive.

As I understand GM will make the Volt fun to drive by, in addition to HP, using appropriate suspension and such.

Art, point taken. My comment was about my lack of enthusiasm about the appearance of the Insight and the Prius, which are the only green cars I have personally driven. I have only read about the instant torque an electric drive provides, but I am looking forward to experiencing it firsthand. I think the production Volt will not be dis-similar in appearance to the Insight/Prius, but the design cues look a bit better, and it sounds like GM is working to give it better handling and a sportier feel, as they should for $40,000.
USBSeawolf is right about the numbers not making a compelling case for the purchase of the Volt at $40,000. But when you throw in the $7500 credit, the sportier look and the ability to live nearly gasoline free, it does give the Volt an allure that the Prius just doesn't have. But the first generation Volt won't make economic sense for most people until the price starts to come down.

This will make great marketing fodder for GM. The calc is the first 40M EV, next EPA comb. cycle 11 mile, burns about .22G so, 51M on .22G of gasoline. I'd be interested to see the numbers for E85. Got to hand it to Lutz and Wagonner - they saw the opening and went through it. Nice work GM.

Thank you, Mr. Goracle, for the warning on the impending hike in electrical rates. It's about time! Electrical cost has been far too cheap considering the environmental damages caused by coal buring and the unforeseen perils from nukes.

The Government should also do the same, warn the people heavily and much in advance, before exacting the Carbon Tax, in a gradual manner, so that people can take proper conservation measures. By carbon taxes, gasoline, and fossil-fuel-based electricity will gradually see a gradual increase in tax rates that will be announced much in advance.

Renewable energy providers such as wind electricity and waste biomass fuels will be given a tax rebate equal the amount taxed, so that it won't be taxed at all!
It's time for a New Direction, everyone. (New Deal was for the last century, New Direction is for this century)

Including oil, nuclear electricity has proven to be the least dangerous method of producing electricity or mechanical energy. Nuclear electricity is carbon negative not carbon neutral because it eliminates the use of carbon fuels. Any carbon used for nuclear fuel or reactor production is displaced in weeks at the most by non-carbon nuclear electricity. In Canada all energy for mining and refining and preparing nuclear fuels could be nuclear electric power.

If evaluated on a full cost basis, Nuclear power is the cheapest way of reducing the production of CO2 and maintaining or increasing electricity availability. The CO2 can be further reduced by combining CO2 with nuclear produced hydrogen to make methanol fuel. It remains more efficient to use nuclear power in electric cars.

Roads and highways have been long proven to be more dangerous than nuclear power plants. Hydroelectric dams have been proven to be more dangerous than nuclear power plants. Per unit energy delivered, windturbines have killed more people than nuclear powerplants including Chernobyl and Three mile Island. Motorcyles should be banned from the US long before nuclear power plants if danger is the criteria. No power plant in the US or France or Japan or England could fail with as many casualties from radiation as Chernobyl did. There were less than 100, and the figure was that high because the Soviets did not take sufficient steps to protect emergency workers.

Every living thing has always had built in radio-activity since life on earth began. Every human or animal body or tree is radio-active waste that will be radio-active for billions of years.

If all the energy used in the US came from Nuclear reactors there would only be about 25 cubic yards of fission products produced every year. This is a cube 3 feet on a side. This figure may be somewhat wrong but it is not ten times as much. Your share would be less than a teaspoon full. If you have been led to believe that there is no room in Nevada to hold 25 cubic yards a year, and you still believe it, relax!, there is a place in New Mexico called WIPP that is approved and is storing such wastes right now. I never knew that Nevada was so small. I wonder what is done with all of the other space between Utah and California.

High energy prices and the Carbon tax will allow any remaining industry and jobs to relocate to China and India.

The US Government has clearly failed to recognize the energy shortage situation in this country and diverted any and all attack monies to the building of nuclear power plants, so that coal and natural gas can be used for making diesel and gasoline.

Iran would be stupid not to build nuclear power plants in stead of using oil for electricity if it thinks it can sell oil to the US for $100 and it did. The US is stupid for not using Nuclear power so that all spare natural gas and coal can be used for automobiles. Nuclear power may be more expensive than coal but it is unlimited as far as the US and Canada are concerned. Right now nuclear power plants in Canada are producing electricity at lower cost than coal plants are producing it. ..HG..

@Henry G.,
Your persistent insistence on Nuclear energy is admirable. But please be reminded that there are safer alternatives to nuclear. You can't blow up the world, nor kill millions of people in one bright flash using solar, wind and waste biomass energy technology.

Nuclear plants may be safe, but the knowledge and skills required to design, build and service these radio-active materials can also turn around to be an instrument of utter evil and destruction the world has never seen before.

The fewer the number of people with nuclear knowledge and skills there will be, the less the risk of nuclear proliferation. The smaller amount of enriched nuclear fuel or waste materials around, the lesser the risk of diverting these toward evil usage. Can't you see that N. Korea and Iran are giving the world headaches? Where are they getting their nuclear materials from? From the nuclear power plants, of course.

Play it safe. Stick to harmless Solar, Wind and waste biomass...throw in it some hydro and geothermal and tidal and wave energy...there you go, inexhaustible energy souces til the end of time. We have a lot of these harmless energy all around...the cost will come down rapidly.

Even if renewable energy is more expensive than fossil or nuclear, the extra money spent on renewable energy will help employ more of our fellow human beings...look around you...How many among us highly trained and qualified people are out of a job? This is unreal! We have human skills and labor ready to get us to adapt to a 100% renewable energy economy TODAY. What it will take is good leadership and understanding and support from everyone.

The figure of 11 cents per kWh is highly misleading.
In city like New York the energy charge is around 12 cents, look similar, however the delivery per KWh is another 8 cents and all taxes and other charges add up to 30 cents per KWh. So 40 miles of charge (8 KWH) will cost: 8 x $0.3 = $2.40, almost a price of gallon of fuel. That not particularly better then standard hybrid like Pirus or VW TDI. I might have sense if you could generate energy at you home from renewal, buy then you need to spend another $16-20K for wind turbine or solar panels.
It look like running on gen set using fuel is more economical then running all electric. That because fuel in US have very few taxes.

Plus it would take 20 years to get new nukes online and by that time we'll all be driving ultra efficient EV's with solar panels in the paneling to power them 30 km a sunny day for free. And we'll have covered every roof and parking lot with solar panels, and wind turbines will be more prevalent so we won't have much need for nukes anyways.

Anyone who thinks Nuclear power is cheap should look at an electric bill from Ontario's O.P.A., but look carefully the cost had to hidden; part under the title 'debt retirement' and the rest in income taxes. More than half of Ontario's power is generated by big nuclear plants.

Henry Gibson:

"Per unit energy delivered, windturbines have killed more people than nuclear powerplants including Chernobyl and Three mile Island."

I would like you to support that claim with evidence.

According to this list the total number of fatalities stands at 61 of which:

• 44 were wind industry or support workers (maintenance/engineers, etc) and one farmer attempting to maintain his own turbine. Most common cause - falls from turbines. Included is one apparent suicide.

• 17 were public fatalities, of which three were from road accidents attributed to "driver distraction of turbines" by police, two were from road accidents involving turbine component transport, one was in a transport accident in which the road collapsed and the driver drowned, one was in a transport accident in which a transport worker lost his leg when loading a trailer and later died, one was from an aircraft accident which hit a new and unmarked anemometer, four were from an further aircraft accident which flew into a turbine in fog (one incident killing four people), one was a 16-year old boy strangled after his necktie became tangled around an unprotected turbine shaft, one was suicide, one was electrocuted, and the remaining accident was the collision of a parachutist with a turbine.

As you can see, wind turbines do not kill innocent people as you try to suggest. All fatalities were people that were willingly and knowingly in the turbine or simply didn't look where they were driving/flying.

Henry, can you produce a similar list of ALL nuclear fatalities including accidents during construction, maintenance and operation of nuclear power plants, fuel enrichment facilities, nuclear fuel transport and processing, uranium mining, and aeroplanes flying into nuclear installations? Then we have a basis to see if your claim is true.

A back of envelope calculation assuming 10 year ownership and only city driving at 10,000 miles a year shows that a break-even fuel cost savings would only begin at around $10/gallon between the purchase of a Volt and a Prius. If the Volt sounds pricey that’s because it is!

@The Goracle (or as I like to think of him; the goral = a little goat :-)

"Off-peak charging: According to a DOE study, If all of the nation's 220 million vehicles were converted to PHEVs using electricity for their everyday driving, 84% of their electricity needs would already be able to be met with our existing infrastructure, thanks to the fact that most would use off-peak charging (via timers). Pure BEV stats should be similar. Not that building new power plants and transmission infrastructure is somehow harder than developing new oilfields."


"electricity needs would already be able to be met with our existing infrastructure"

Yes! The existing infrastructure that currently causes rolling brownouts due to it's lack of capacity.


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