Summary of Interagency Working Comments Received on Draft Rule under EO 12866 Review.  Subject to

Further Policy Review

1

Below is a summary of interagency comments received during EO 12866 review of the draft rule

“Revisions to Motor Vehicle Fuel Economy Label.” They are for your consideration and subject to further

policy review.  

Draft Preamble Section II.B.4.a 

a. Fuel Combustion/Electricity Generation GHG Issues 

This section discusses how the agencies plan to address the issue of greenhouse gas 

emissions associated with the use of motor vehicles, in the context of a program specifically 

designed to provide consumers with information that will be useful when purchasing a vehicle. 

The agencies’ approach takes into account (1) the limited amount of information that can be 

provided on a label, (2) the importance of simplicity, clarity, accuracy, and intelligibility on the 

label, (3) the fact that the law requires a great deal of information to be presented on the label, 

and (4) the ability to provide the public with additional and comprehensive information in a 

consumer-friendly format on a website.1

 This discussion focuses on, but is not limited to, the 

advanced technology vehicles that use electricity from the grid to power vehicles, such as the 

electric vehicles and plug-in hybrids that are expected to enter the market in larger numbers in 

the coming years; the discussion also refers to the use of renewable fuels in gasoline-powered 

vehicles. 

As explained below, our proposed approach would limit the label to tailpipe-only 

emissions while providing much fuller information on a website. But we also identify, and seek 

comments on, alternative approaches, also designed to accommodate the relevant variables. 

The agencies recognize that all automotive fuels have “lifecycle” GHG emissions 

associated with the production and distribution of the fuel used by the motor vehicle. Lifecycle 

GHG emissions are associated with gasoline, diesel, and other fuels such as natural gas, 

electricity, and renewable biofuels. For example, electricity is used to charge EV or PHEV 

batteries, and such electricity use produces greenhouse gas emissions. The agencies also 

recognize that tailpipe-only emissions provide important but incomplete information and that a 

significant number of consumers may want, or benefit from, access to information on the total 

GHG emissions associated with the operation of their vehicles. Electric vehicles do not have any 

tailpipe emissions since their motors do not burn fuel, but the electricity used to power such 

vehicles does produce GHG emissions, and consumers might seek, or benefit from, a label that 

                                                           

1

 On the relationship between summary disclosure, as on the label, and full disclosure, as on the website, see [OIRA 

guidance document]. 
Summary of Interagency Working Comments Received on Draft Rule under EO 12866 Review.  Subject to

Further Policy Review

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allows for simple and accurate comparisons across vehicles. However, the agencies emphasize 

that developing such information, and providing it to consumers in a manner that is accurate and 

meaningful, raises a number of challenging issues. 

It is true that in principle, a full lifecycle evaluation could potentially include an 

evaluation of a comprehensive set of GHG and energy impacts associated with both the vehicle 

(extraction and processing of materials, energy used in assembly, distribution, use, and disposal, 

etc.), and the fuel (feedstock extraction, feedstock transport, fuel processing, fuel transport, 

indirect effects, etc.). And if a full or nearly full accounting could be provided in a clear and 

intelligible form, there would be advantages to providing it on the label to consumers. In 

practice, however, offering even the more limited accounting for GHG emissions from 

production and distribution of the fuel, including electricity, presents complex challenges. EPA 

currently does not measure fuel combustion/electricity generation GHG emissions in its vehicle 

testing—although on an average basis GHG emissions are a function of MPG or KwH per mile 

and thus could in principle be calculated (as has been done for fuel economy, the central metric 

on labels in the past). The agencies recognize that modeling can be performed to assist in 

estimating these emissions. But in developing fuel combustion/electricity generation GHG 

emissions values, modeling would need to be done carefully to avoid inaccuracy and consumer 

confusion, especially in light of variations across time and across regions. For example, GHG 

emissions from electricity generation will vary significantly in the future, based on the different 

fuels used at generating stations -- perhaps by as much as an order of magnitude between coal 

and non-fossil feedstocks. The Energy Information Administration (EIA) provides estimates of 

the future electricity generation mix, so there may be some basis for estimating future GHG 

emissions based on current state and federal policies, but these estimates will inevitably rest on 

some uncertain assumptions. 

It is true that the EPA has undertaken extensive lifecycle modeling of biofuels for the 

Renewable Fuel Standard rulemaking in response to the requirements of the Energy 

Independence and Security Act. But that assessment was done in the context of the particular 

mix of biofuels required nationally in 2022 by the Act, with a series of assumptions and 

estimates that may not be accurate either today or in 2022. 

One overriding issue is whether the agencies could reasonably provide a single, national 

value for GHG emissions from electricity generation or could provide instead different values 

customized for various regions of the country.2

 A single, national value would have the 

advantage of simplicity, and it could be identified with appropriate caveats. For individual 

                                                           

2

 See http://www.eia.doe.gov/energyexplained/index.cfm?page=electricity_in_the_united_states for an overview of the national U.S. electric 

power industry net generation by fuel type. 
Summary of Interagency Working Comments Received on Draft Rule under EO 12866 Review.  Subject to

Further Policy Review

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owners, however, a single national value would generally not be accurate, and the individual 

would need access to additional information, such as regional values, to evaluate the impact of a 

specific vehicle.3

 (It is true that similar caveats apply to other information provided on the label, 

such as cost savings based on representative fuel prices and miles travelled.) In addition, the 

agencies would have to decide (1) whether to use average or marginal (i.e., reflecting the fact 

that increased vehicle demand might change the overall mix of electricity sources) GHG 

emissions factors, and (2) if the marginal approach is used, whether to assume all nighttime 

charging or a mix of daytime and nighttime charging. Another major consideration is whether to 

base electricity generation GHG emissions values on today's electricity markets or on projected 

changes in electricity markets that might occur by 2020 or some other year (note that vehicles 

produced in the next few years will remain in the fleet for 15 or 20 years or more). 

Some states have already passed legislation that could require major changes in how 

electricity is produced in those states in the future, and Congress has considered landmark 

legislation as well. It is clear that the question of how electricity will be produced in the future is 

a very fluid issue. As a result of the Energy Independence and Security Act biofuel mandates, 

the agencies expect the amount of biofuel in the transportation fuel market to increase 

significantly over time, and the contribution of feedstocks to change over that time as well. 

Information that addresses lifecycle emissions of biofuels would need to take these 

considerations into account. 

Currently, the agencies believe that all of these complex factors can be best addressed by 

providing a great deal of relevant information on a website, which can go into great depth and be 

changed and updated as appropriate. Unfortunately, we do not now have a full lifecycle analysis 

or fuel combustion/electricity generation analysis from which to draw for labeling purposes 

across the full range of vehicles and fuels. The data reported to EPA on emissions from fuel 

production vary across fuel types and is much more detailed for gasoline production. At the 

present time, it would be difficult to represent emissions from energy generation on a national 

label in a way that is both useful and accurate for consumers, given regional variations, how 

generation within regions is dispatched, and access to green power purchases. 

 Therefore, EPA and NHTSA are proposing that the label should limit itself to tailpipe 

only emissions (clearly identified as such) and include a more complete discussion on energy 

generation and lifecycle analysis on the webpage at this time. We believe that this approach will 

prove sufficiently informative to consumers. It also allows us the opportunity to provide a fuller 

discussion of GHG emissions associated with energy generation for alternative vehicles, as well 

as emissions from fuel production (gasoline and biofuels). For example, a website could provide 

calculator tools that could reflect regional variations in the GHG emissions associated with 

                                                           

3

 Regional values could be provided on a web site. EPA has a website (http://www.epa.gov/cleanenergy/energy-and-you/how-clean.html) on 

which consumers can enter their zip code and find out what fuel mix is used to produce the electricity they use.
Summary of Interagency Working Comments Received on Draft Rule under EO 12866 Review.  Subject to

Further Policy Review

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electricity generation as well as use national averages. A website could also provide information 

on the projected fuel lifecycle impacts associated with biofuels. The website could be updated 

over time as the mix of electricity fuel sources and biofuels changes. This approach could help 

the consumer understand over the lifetime of their vehicles how their electricity generation 

emissions impacts might be changing. 

The agencies acknowledge that many more consumers will look at the label than at the 

website, and that there is a risk that to some consumers, the proposed label, limited to tailpipe 

emissions, might not provide accurate information. In particular, a “0” figure for GHG emissions 

might prove confusing to some consumers. While accurate and more complete information will 

be provided on the website, putting 0 grams CO2/mile on the label may lead some consumers to 

misperceive that driving their EV does not contribute to GHG emissions. The agencies also 

acknowledge that if accurate and sufficiently complete information could be provided on the 

label in a simple and intelligible way, there would be significant advantages in attempting to do 

so. 

At this point in time, however, any such effort could well produce undue confusion. A 

label that clearly and conspicuously limits itself to tailpipe emissions appears to be the best 

available way to combine accuracy and disclosure, so long as fuller information is available on 

the website. The agencies believe that even though many consumers will not visit the website, it 

will be used by many groups and organizations, and as a result, the information that it provides 

will be made available and used in the marketplace. We seek comment on our current view that 

the web is the better place, compared to the label, to address the complex issues associated with 

emissions associated with electricity generation and lifecycle emissions more generally. 

The agencies also believe that the proposed approach is consistent with the Energy Policy 

and Conservation Act (EPCA), as amended by the Energy Independence and Security Act 

(EISA) of 2007, which states that NHTSA must require vehicles to be labeled with information 

“reflecting an automobile’s performance ... [with respect to] greenhouse gas ... emissions ... of 

the automobile.”4

 NHTSA believes that a reasonable interpretation of this provision is that only 

GHG emissions directly from the vehicle itself are required for the label. Those would be the 

direct “automobile’s performance” with respect to “greenhouse gas emissions.” NHTSA 

believes that it would also be reasonable to interpret the statutory language such that the required 

label information on GHG emissions would include information on the fuel 

combustion/electricity generation GHG emissions associated with electricity or other fuels used 

by the vehicle, insofar as these GHG emissions are directly related to the automobile’s GHG 

performance. 

                                                           

4

 49 U.S.C. 32908(g)(1)(A)(i). 49 U.S.C.32908(g)(1)(A)(ii) also refers to GHG “emissions of automobiles,” and further requires a designation of 

automobiles “with the lowest greenhouse gas emissions over the useful life of the vehicles.” 
Summary of Interagency Working Comments Received on Draft Rule under EO 12866 Review.  Subject to

Further Policy Review

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We invite comment on the proposed approach. For example, we encourage commenters 

to be as specific as possible with any recommendations on how to address fuel 

combustion/electricity generation GHG emissions on the website. If information on these 

emissions is to be provided on a website, exactly what information? The agencies specifically 

invite comment on how to address fuel combustion emissions associated with the electricity used 

to power the advanced technology vehicles starting to enter commerce, electric vehicle, and 

plug-in hybrid vehicles. The agencies also invite comment on how to address full GHG 

emissions from biofuels on a website. Should emissions be identified specifically for the 

emissions associated with the combustion of fuel to produce electricity? Should such emissions 

be determined on a regional or a national basis? Should these emissions be provided as a relative 

comparison to a gasoline or diesel fuel, the current predominant fuels? 

For the convenience of commenters, we have prepared the table below as an illustrative 

example of one simplified way that some lifecycle emissions information could be accounted for 

on a website, based on certain assumptions.5

 Consistent with the discussion above, it is 

important to emphasize that the tailpipe + lifecycle values in the table below are based on 2005 

national average electricity GHG emissions, and could be very different for certain regions of the 

country today and for the nation in the future if there are major changes in the mix of methods 

used to generate electricity or in the GHG emissions associated with its generation. 

 Proposal--TailpipeOnly Tailpipe + Lifecycle 

Vehicle CO2/mile CO2/mile 

EV 0 197 

PHEV 1 89 210 

PHEV 2PHEV 2 133 217 

Toyota Prius HEV 178 224 

Honda Civic HEV 212 266 

                                                           

5

    The key assumptions underlying the illustrative numbers in the right-hand column are that:EV and PHEVs all assumed to use 200 Watt-hours 

per mile when operating on electricity over the EPA test and assuming a 30% range (43% electricity consumption) shortfall from test to road. 

 PHEV 1 assumed to operate on electricity 50% of the time. 

 PHEV 2 assumed to operate on electricity 25% of the time. 

 Uses 2005 nationwide average value of 0.642 grams of GHG per Watt-hour at powerplant (adjusted to include GHG emissions from 

feedstock extraction, transportation, and processing as well) from MY2012-2016 light-duty vehicle GHG final rule (75 Federal 

Register 25437). 

 Assumes typical 7% electricity grid transmission losses. 

 Uses 2250 grams GHG per gallon of gasoline.

Comment [A1]: Suggest the first three list the

vehicle, as others do, since not all EVs and PHEVs

perform equally
Summary of Interagency Working Comments Received on Draft Rule under EO 12866 Review.  Subject to

Further Policy Review

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Honda Insight HEV 217 273 

Ford Fusion HEV 228 287 

In general, for purposes of providing information on the web, the agencies invite 

comment on the appropriate metrics to use and the specific suggestions for content and format, if 

appropriate. The agencies also request comment on which web resources it should prioritize for 

development that would provide the most useful information to consumers. 

With respect to the label itself, the agencies are also requesting comment on alternative 

options for the label for EVs, PHEVs, and FFVs that is under serious consideration, similar to a 

co-proposal. Under one version of this alternative, the EV label would continue to reflect the "0" 

CO2g/mile number currently displayed on the co-proposed labels (Figures III-2, III-10), but the 

label would be modified by adding either a symbol or an asterisk and explanatory text which 

states, "The only C02 emissions are from electricity generation." Likewise, the agencies would 

modify the co-proposed PHEV labels (Figures III-3, III-6, III-1, III-12) inserting either a symbol 

or asterisk next to the current CO2g/mile number displayed with the following explanatory text, 

“Does not include CO2 from electricity generation.” In addition, under this alternative, FFV 

labels (for FFV vehicles only) would continue to reflect the gasoline only CO2g/mile number 

currently displayed on the co-proposed labels (Figures III-8 and III-14), but the label (for FFVs 

only) would be modified by adding either a symbol or an asterisk and explanatory text which 

might state, “The CO2 emissions listed here are from fossil fuel combustion only. They do not 

reflect the use of renewable biofuels. (See owner’s manual for more information on the 

renewable nature and environmental benefits of using alternative fuels. Information also 

available at website www.fueleconomy.gov).”

This alternative might provide more accuracy and clarity for purchasers by more explicitly 

indicating that the CO2 emissions from generation of electricity are not reflected in the CO2 

numbers on the label. The agencies request comment on this alternative option. 

Another version of this alternative would be to use not a “0,’ but only a symbol or 

asterisk for EVs and PHEVs, alongside an explanatory text saying, “The only CO2 emissions are 

from electricity generation.” The agencies invite comment on whether such an approach would 

be superior to the proposed approach in terms of combining accuracy and intelligibility. 

In addition, the agencies invite comment on the feasibility and usefulness of an 

alternative approach that would include emissions from electricity generation or fuel combustion 

on the label as well as on the website. A label including the fuel combustion and electricity 

generation emissions could be based on national average assumptions, similar to the national 
Summary of Interagency Working Comments Received on Draft Rule under EO 12866 Review.  Subject to

Further Policy Review

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averages used to calculate fuel costs for electric vehicles (12 cents per KW hour), fuel price on 

the label ($2.80), and the number of miles travelled per vehicle per year (15,000). For electricity 

generation, the agencies would make assumptions about the overall impact on electric car 

recharging on the grid mix, which would include making assumptions about the time-of-day 

distribution of recharging and the subsequent impacts on the base and peak load electricity 

generation. Under this approach, the label could have an asterisk noting that the approximation 

is based on current national average emission rates from electricity generation, and that a 

forecast of future fuel combustion/electricity generation GHG emissions (and possibly other data 

associated with the particular circumstances of recharging of the vehicle’s batteries) can be 

found on the website. The label could also note that the fuel production and distribution 

emissions are based on a national average (as is the case with gasoline and electricity prices and 

vehicle usage used the generate label information). 

This alternative approach may have advantages for consumers who, for whatever reason, 

choose not to visit the website, or are unable at the point of sale to obtain more precise 

information regarding their particular circumstances. In view of the foregoing discussion, 

however, identifying the many assumptions the agencies would need to make to conduct such an 

analysis, we believe that this alternative would have to overcome several serious difficulties. We 

ask for comment on whether and how each of the challenges outlined above for consideration for 

a website could be addressed if considered for a label. 

 The agencies also recognize that not all EVs are created equal – some will require much 

more energy per mile traveled than others, and using a single value of zero grams of CO2per mile 

may not sufficiently inform consumers about the divergent emissions impacts of different EVs,. 

Over time, the agencies note that we will continue to provide detailed information about the 

lifecycle GHG impacts of different vehicles on the website, and will continue to consider 

whether and how GHG labeling could move closer to a full lifecycle basis.