Summary of Interagency Working Comments Received on Draft Rule under EO 12866 and EO 13563

Review.  Subject to Further Policy Review

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Below is a summary of interagency comments received during EO 12866 and EO 13563 review 

of the draft final rule establishing GHG emissions standards and fuel efficiency standards for 

medium and heavy duty trucks. They are for your consideration and subject to further policy 

review. 

1) Probabilistic Uncertainty Analysis OMB Circular A-4 states, “For major rules involving 

annual economic effects of $1 billion or more, you should present a formal quantitative 

analysis of the relevant uncertainties about benefits and costs. In other words, you should try 

to provide some estimate of the probability distribution of regulatory benefits and costs. In 

summarizing the probability distributions, you should provide some estimates of the central 

tendency (e.g., mean and median) along with any other information you think will be useful 

such as ranges, variances, specified low-end and high-end percentile estimates, and other 

characteristics of the distribution.” 

The RIA does not include a formal probabilistic uncertainty analysis. Please provide this 

analysis. 

2) Estimates of costs and benefits 

Several reviewers had concerns about the timeline used to estimate the rule’s costs and 

benefits. Costs and benefits of model year 2014 to 2018 standards have been estimated for 

every year from 2012 to 2050 as if the 2018 standards remain in place for model years 

through 2050. This results in the aggregate estimates of costs and benefits being largely 

driven by long-term values (i.e., beyond 2020) associated with the impacts of the standards 

on trucks manufactured decades in the future. However, both costs and benefits are 

measured against a baseline fuel economy associated with MY 2010 vehicles that is assumed 

to remain constant through 2050. The selection of a constant baseline is problematic for 

estimating long-term costs and benefits, particularly given assumptions about declining 

technology costs and increasing fuel prices. For example, if historical trends in fuel economy 

improvements continue into the future, there should be a point at which, even in the baseline, 

vehicles would exceed the standards proposed here. In such a case, the standards would 

become non-binding, and, beyond that point in time, the program would neither impose costs 

nor produce benefits. 

More generally, given that the question at hand relates to the merits of standards for MY 

2014 to MY 2018, and the standards will almost certainly be revisited in response to new 

information in future years, the results of analysis of these standards should not be driven, as 

they currently are, by estimates of the standards’ effects on trucks manufactured decades into 

the future. 

In light of the above, commenters suggest that EPA and NHSTA re-evaluate the approach 

taken to presenting estimates of costs and benefits, and shift the focus of this analysis to the 
Summary of Interagency Working Comments Received on Draft Rule under EO 12866 and EO 13563

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near- and medium-term costs and benefits of the rule. Commenters recommend that agencies 

estimate costs and benefits for only MY 2014 to MY 2018 trucks, over their estimated useful 

lifetimes. Presumably, this would not require new analysis, but rather simply altering what is 

drawn from the existing analysis to present in the preamble and RIA. 

This rule’s primary direct effect will be on the emissions and fuel economy of MY2014 to 

MY2018 vehicles, and the standards can be adjusted for subsequent model years. 

Consequently, as a matter of good regulatory analysis, commenters recommend that the 

agencies focus their analysis of the rule’s costs and benefits on its implications for MY2014-

2018 vehicles alone. Given that most of the trucks contributing to the 2030-2050 net benefit 

results will presumably be post-2018 model year trucks, a discussion of the rule’s overall 

net benefits from 2030 onward seems to be an unnecessary distraction. Commenters note 

that the agencies selected the standards based on their implications for MY2014-MY2018 

trucks, not based on the implications of the standards if they were to remain in place through 

2050. The regulatory analysis should therefore reflect this focus. 

3) Annualized Estimates of Costs and Benefits using Model Year 2014-2018 analysis.

Commenters also recommend that agencies include summary tables of annualized costs and 

benefits using 3 and 7% discount rates using model year 2014-2018 analysis. Please include 

these tables in the summary of the Preamble and the RIA. 

4) Averaging, Banking, and Trading Provisions 

Regarding the averaging, banking, and trading provisions (Section IV. A of the preamble), 

EPA/NHTSA have increased the flexibility of these provisions relative to the proposed rule. 

However, the agencies are maintaining some restrictions on averaging and trading, 

specifically those between vehicle weight classes and between engine subcategories. In 

explaining their rationale for restricting averaging and trading between vehicle weight 

classes and engine subcategories, the agencies make two key arguments. 

The first of these two arguments is economic in nature (pp. 255 – 256): 

“a manufacturer that produces both engines and heavy-duty highway vehicles could mix 

credits across engine and vehicle categories to gain an advantage over competitors that 

are not integrated. Limiting credit ABT to within each engine averaging set and not 

allowing it between engines and vehicles will help prevent a competitive advantage due 
Summary of Interagency Working Comments Received on Draft Rule under EO 12866 and EO 13563

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solely to the regulatory structure. Similarly, large volume manufacturers of engines 

could shift credits between heavy heavy-duty diesel engines and light heavy-duty diesel 

engines to gain an advantage in one subcategory over other manufacturers that may not 

have multiple engine offerings over several regulatory engine subcategories.” 

a) Interagency commenters have concerns about this language on several levels, and raised 

concerns about similar language in early versions of the draft proposed rule before that 

language was rephrased to make clear that it reflected views of industry participants and not 

necessarily views of the USG. Commenters request clarity on why the agencies are 

endorsing this view and request that agencies provide basis for this concern. 

Commenters note that not all industry participants raised this concern. 

b) Further, the agencies’ concern about not creating “a competitive advantage due solely to the 

regulatory structure” could actually argue strongly against limiting trading as the agencies 

have proposed. Specifically, relative to allowing more flexibility, limiting averaging and 

trading necessarily increases the cost of compliance for certain high-cost manufacturers 

within an “averaging set”. Therefore, by foreclosing averaging and trading across averaging 

sets, to the extent that there are particular manufacturers that are technology leaders in a 

particular averaging set, the proposed restrictions will effectively raise the compliance costs 

of those manufacturers’ rivals to a greater extent than would occur if broader trading were 

allowed. In turn, this will provide a greater, regulatory-induced competitive advantage to 

such manufacturers, and will adversely affect consumers too. In light of this concern that 

the proposed approach could work at cross purposes with the agencies’ goal of 

avoiding adverse effects on competition and consumer welfare, commenters 

recommend that the agencies give further consideration to the ultimate effects of their 

proposed restrictions on averaging and trading. 

c) The second argument that the agencies make to support their position is that: 

“[trading/averaging] credits between averaging sets of engines would be problematic 

because of the differences in regulatory useful lives. The agencies want to avoid having 

credits from longer useful life categories flood shorter useful life categories, adversely 

impacting compliance with the final CO2 and fuel consumption standards in the shorter 

useful life category.” (p. 256) Can the agencies clarify why this concern about trading 

of credits associated with different regulatory useful lives could not be addressed by 
Summary of Interagency Working Comments Received on Draft Rule under EO 12866 and EO 13563

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simply incorporating information on regulatory useful life in determining how many 

credits are awarded for each regulated engine or vehicle type? 

5) Upstream emissions. 

Commenter notes that if the objective of the rule is to reduce national GHG emissions as the 

agencies claim in this Preamble and RIA, then commenters strongly recommend that future 

EVs or other related electric technologies etc be responsible for the national average GHG 

emissions from electric power generation. Please revise rule and discussion accordingly. 

6) Advanced Technology Credits 

Both for its direct implications in this rule and for its precedential implications, commenters 

would appreciate additional clarity from the agencies regarding how they settled on the 

chosen crediting multiplier and limits on credit use for advanced technology credits. 

7) Analysis of Alternatives 

Regarding the analysis of alternatives, the agencies have partially responded to previous 

interagency comments during proposed rule phase and have added to the RIA and preamble 

tables that summarize the monetized net benefits of each alternative for the lifetime of 

MY2014-2018 vehicles (Tables 6-22 and 6-23 on pages 6-16 and 6-17 of the RIA, and tables 

IX-4 and IX-5 in the preamble). Commenters are pleased that the agencies have added this 

information. However, commenters are concerned that the numbers presented may not have 

been calculated correctly, given some puzzling results contained in those tables. 

In particular, one table presents results with monetized net benefits calculated at a 3% 

discount rate while the other table uses a 7% discount rate. In comparing the two tables, and 

focusing only on the first two lines of results for truck program costs and fuel savings, it can 

be seen that the change from a 3% discount rate to a 7% discount rate reduces monetized 

program costs by about 60%, whereas monetized fuel savings decline by only about 30%. 

This result is counterintuitive, given that the program costs for MY2014-2018 trucks will be 

almost entirely near-term capital costs whose monetized NPV should not be significantly 

affected by a change in discount rate. On the other hand, fuel savings accrue over a longer 

timeframe and so should be more (not less) affected by the choice of discount rate. The 

numbers also appear to be inconsistent with similar estimates for only the preferred 

alternative that appear in preamble tables VIII-34 and VIII-35. 
Summary of Interagency Working Comments Received on Draft Rule under EO 12866 and EO 13563

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Commenters recommend that the agencies check the data underlying tables 6-22 and 6-23 

of the RIA (IX-4 and IX-5 of the preamble), and provide the interagency reviewers with 

updated, corrected versions. If possible, please provide more detailed data underlying the 

table to ensure that the numbers are accurate. 

8) Also regarding the analysis of alternatives, while tables 6-22 and 6-23 (once corrected) will 

allow for a comparison of the monetized net benefits of an overall alternative in aggregate 

across all model years, the tables present aggregate information on the entire set of 

regulatory subcategories (e.g., vehicle weight classes) and for all model years included in 

the rulemaking. However, the RIA does not currently present net benefit calculations for 

the alternatives with respect to individual subcategories or model years, which would allow 

reviewers to establish that the selected regulatory alternative was the one that maximizes net 

benefits for each subcategory (e.g., pickups and vans, vocational vehicles, and combination 

tractors) and model year. During review of the proposed rule, agencies requested that this 

information be added to the RIA, given that the agencies have flexibility with respect to the 

choice of standards for each model year and for each regulatory subcategory. 

Commenters request that the agencies provide versions of Tables 6-22 and 6-23 for 

each subcategory and model year (2014-2018). 

9) Accounting for Uncertainty in Analysis of the Alternatives 

The agencies note that, whereas Alternatives 2 and 3 (the preferred alternative) are believed 

to be achievable in the proposed timeframe, Alternative 4 (the next most stringent 

alternative) could have far higher costs because agencies “do not believe that these 

technologies can be developed and introduced in the timeframe of this rulemaking.” 

Effectively, the agencies are arguing that there is a “knee” in the cost curve and that they 

have chosen the stringency just to the left of that knee. 

Commenters request agencies to provide a full probabilistic uncertainty analysis. In addition, to 

the extent that the agencies believe that a knee in the cost curve exists just beyond the preferred 

alternative, as they have suggested, commenters suggest that the agencies at least provide some 

discussion of the implications of cost uncertainty for the expected value of its preferred 

alternative, versus Alternative 2, the less stringent alternative. 
Summary of Interagency Working Comments Received on Draft Rule under EO 12866 and EO 13563

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Specifically, if the exact location of the knee in the cost curve is unknown, then the expected cost 

of the preferred alternative (Alternative 3), taking into account this uncertainty, could be 

considerably higher than the most likely cost, as forecasted by the agencies. By contrast, as 

Alternative 2 is further to the left from that knee, this cost uncertainty will have less of an effect 

on the expected cost of Alternative 2, relative to its most likely cost as projected by the agencies. 

This has important implications for not only the net benefits of Alternative 3, but also for the 

relative merits of Alternatives 2 and 3. Commenters would appreciate the agencies’ views on the 

implications of cost uncertainty for the expected cost of, and their choice of, the preferred 

alternative, given the apparent knee in the cost curve just beyond Alternative 3. Further, 

commenters recommend that the agencies include a discussion of the implications of cost 

uncertainty, in light of this knee in the cost curve, in the preamble and RIA. 

10) The text in preamble section IX, p. 491, incorrectly references Table 2.35 in the RIA. The 

correct table is 2.36 in the RIA. Several table references in the text in Chapter 2 of the RIA 

are incorrectly numbered.

11) The RIA defines the No-Action Option as an alternative. The presentation would be clearer 

(and more accurate) if this discussion was framed as a discussion of the choice of baseline 

for analysis. This might be particularly true given that the section discusses two alternative 

baselines. If the exposition followed this format, it would facilitate later analysis of the 

alternatives considered in comparison with these baselines. Commenters hence suggest 

removing lines for Alternative 1 (and 1a) from Tables 6-19 through 6-23. 

12) Commenters recommend that the costs and emissions for the proposal and the alternatives 

be presented relative to each of the baselines. Commenters recommend that the agencies 

analyze the costs and benefits of the AEO 2011 Baseline as well. Please include these in the 

RIA and preamble. s 

13) Commenters recommend a fuller explanation of why agencies cannot rely upon market 

effects to solve this problem when fuel savings of the program are estimated to be five times 

the cost of the program. 

14) Commenters recommend that the agencies include fuel savings in the benefits category 

throughout the entire Preamble and RIA tables and discussion. Please make this change. 

15) RPE and Learning curve: Please discuss the rationale for deviating from the NAS 

recommendation on RPE. Also, please provide evidence for the time learning curve used in 
Summary of Interagency Working Comments Received on Draft Rule under EO 12866 and EO 13563

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the analysis. Given that the regulation doesn’t appear to be very technology forcing, please 

provide evidence for taking 2 learning curve discounts, which serves to lower the cost of the 

rule and is in total is a more aggressive learning curve then the agencies have used in the 

past. Please clearly present the costs with and without learning discounts (probably in a 

tabular form would be the best). Also, how were the fixed costs spread over the relevant 

trucks/trailers? 

16) Tires: How does this NPRM affect the retreading of tires? Is there any weather-related 

safety concern with reduced tire rolling resistance? 

17) Time value associated with reduced refueling: How many refills in the baseline? What is 

the assumed time saved per refill? 

18) Many commenters request that agencies remove reference to the GDP analysis (memo to 

docket on “economy-wide modeling..”) from the Preamble and the RIA. 

19) The RIA does not include a market failure discussion. Without this discussion, the agency 

has no compelling reason to characterize private fuel savings that accrue to firms as social 

benefit.

20) Baseline 

 Commenters request a better understanding of how SmartWay is projected to affect the 

baseline? The current discussion states that SmartWay has “saved 1.5 billion gallons of 

diesel fuel as well as $3.6 billion in fuel costs” (p. 1-34). 

 What is the baseline fuel consumption assumed? 

 What is the fleet make-up assumed? 

 Commenter recommends that the “No action” alternative be moved to the baseline 

discussion. 

21) Effect of the rule 

 Will this rule and standards established affect the fleet make-up? If so, how does this 

affect the benefit and cost estimates? 

o NAS Report makes three findings regarding fleet make-up: 

 Finding 6-12. Standards that differentially affect the capital and operating 

costs of individual vehicle classes can cause purchase of vehicles that are 

not optimized for particular operating conditions. The complexity of truck 

use and the variability of duty cycles increase the probability of these 

unintended consequences. 

 Finding 6-16. Some fuel efficiency improving technologies will add 

weight to vehicles and push those vehicles over federal threshold weights, 

thereby triggering new operational conditions and affecting, in turn, 
Summary of Interagency Working Comments Received on Draft Rule under EO 12866 and EO 13563

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vehicle purchase decisions. More research is needed to assess the 

significance of this potential impact. 

 Finding 6-17. Some fuel efficiency improving technologies will reduce 

cargo capacity for trucks that are currently “weighed-out” and will 

therefore force additional trucks on the road. More research is needed to 

assess the significance of this potential impact. 

22) Tire market discussion 

 Commenter requests reference to discussion or including new discussion on the 

difference between rolling resistance vs. traction, and how this rule will affect both. 

 Commenter requests that the agencies provide basis (e.g., citation, etc.) for the 

following: 

i. Baseline tires are assumed to have RRc=7.8 (steer) and 8.2 (drive) for 

combination tractors and RRc=9.0 for vocational vehicle. (Table 2-1) 

ii. The cost estimate of $7 (e.g., $1.75/tire) for Class 2b trucks and $10 (e.g., 

$2.5/tire) per Class 3 trucks/vans (p. 2-21). 

iii. EPA and NHTSA project a cost of $68 ($2009$) for low rolling resistance 

steer tires (2 per truck) for both Class 7 and 8 tractor including a low 

complexity ICM of 1.18. For low rolling resistance tires, the agencies 

estimate truck-based costs of $63 (2009$) and $126 (2009$) for Class 7 and 8 

tractors, respectively, including a low complexity of ICM of 1.18. (p. 2-51) 

What is the length of time for these cost estimates? Yearly? 

iv. Please explain the retread cost savings of $1600 to $2000 per tractor. (p. 2-54) 

23) Alternatives: It looks like Alternative 4 (20% more stringent than preferred alternative) 

maximizes net benefits. During the EPA/NHTSA briefing, the agencies explained that this 

Alternative is based on a bench-scale technology that is not commercially available. Given 

this technology constraint, commenters suggests that the agency provide an assessment of 

likelihood of fuel savings instead of the currently provided point estimate. Same comment 

applies to the most stringent alternative. Also, are the estimates provided incremental in 

nature? 

24) Please provide summary of all public comments to this rule. The Preamble does not include 

this and it must be part of the Preamble, not as a separate document as stated in Preamble. 

Please provide this full summary of comments. 

25) How does learning affect the total cost estimate? What is the projected cost without any 

learning? 

26) Interagency commenters suggest that the agencies remove the employment impacts 

discussion from the Preamble and the RIA. The discussion does not seem to add any value, 

and because it is speculative, commenters suggest it be removed. 
Summary of Interagency Working Comments Received on Draft Rule under EO 12866 and EO 13563

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27) Market Failure discussion from Preamble currently states: 

“It is often asserted that there are cost-effective fuel-saving technologies that truck 

companies are not taking advantage of. This is commonly known as the “energy gap” or 

“energy paradox.” ” 

The energy paradox is more broad than just for truck companies, so commenters 

recommend that the agencies phrase this as: 

“It is often asserted that there are cost-effective fuel-saving technologies that markets do not 

take advantage of. This is commonly known as the “energy gap” or “energy paradox.” “ 

Or, 

“It is often asserted that there are cost-effective fuel-saving technologies that consumers fail to 

recognize, or that producers fail to incorporate into their products. This is commonly known 

as the “energy gap” or “energy paradox.” ” 

28) Has EPA considered creating an incentive program so that consumers fully internalize the 

benefits of investing in fuel saving technology? 

29) Commenter recommends deleting the following sentence on page 368 of the Preamble “The 

NRC assessment is a clear affirmation that the scientific underpinnings of the 

Administrator’s Endangerment Finding are robust, credible, and appropriately characterized 

by EPA. Commenters request this deletion becusae NAS did not review underpinnings and 

do not mention these. 

30) Commenters request the agencies to provide full citations of the discussion found from page 

369 through 376. There are no citations provided and it is very unclear whether this 

language is pulled verbatim from a particular document or if it is original agency text. 

Unless they are direct quotes, citations are always needed for all statements of scientific 

facts. 

31) Commenter requests that the next to last sentence on page 373 read: “Thus, the potential 

impacts of climate change raise potential environmental justice issues, depending on 

direction of potential impact.” 

32) Commenter recommends deletion of footnote 3 on page 5 because it is not necessary for 

rulemaking at hand. 
Summary of Interagency Working Comments Received on Draft Rule under EO 12866 and EO 13563

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33) Commenter requests evidence for the claim on page 9 that “world crude oil production is 

highly concentrated, exacerbating the risks of supply disruptions and price shocks as the 

recent unrest in North Africa and the Persian Gulf highlights.” 

34) page 13. Commenter requests clarity from agencies on why the following section is included 

in the Preamble. Please provide clarity on the relevance of these benefits to the rulemaking 

under current review: “As a result of these programs, new vehicles meeting current emission

standards will emit 98% less NOX and 99% less PM than new trucks 20 years ago.  The resulting

emission reductions provide significant public health and welfare benefits.  The most recent EPA

regulations which were fully phased‐in in 2010, the monetized health and welfare benefits alone

are projected to be greater than $70 billion in 2030  – benefits far exceeding compliance costs and

not including the unmonetized benefits resulting from reductions in air toxics and ozone precursors

(66 FR 5002, January 18, 2001).”

35) Are tons in g/ton-mile measured (and tested) at vehicle max capacity? 

36) Page 23 table 1-2. Why is the high roof sleeper cab standard lower than the mid-roof? 

37) Is maximum feasible the only condition in EISA or are there other conditions to be met in 

setting standards? 

38) It is not clear from Preamble what comments were received on safety impacts from tire 

rolling resistance assessment. Please summarize comments on this topic. 

39) Page 88 regarding vehicle speed limiters. Are there any safety benefits or time costs from 

vehicle speed limiters? 

40) The agencies don’t seem to have responded to this point in the Preamble on page 124. 

Please provide response to this comment: 

“That supplier also indicated that a correlation of a 20 percent reduction in rolling resistance

achieved through tread depth reduction could lead to a 30 percent decrease in tread‐life and 15

percent reduction in wet traction.  The agencies note that when they inquired about potential

‘safety’ related tradeoffs, such as traction (braking and handling) and tread wear when applying

low rolling resistance technologies, tire suppliers consistently responded that they would not

produce a tire that compromises safety when fitted in its proper application.”

41) Commenters recommend that the agencies either delete this section on page 327 or provide 

basis for this claim. It seems to indicate that market works after regulation but not before. Is 

it because of in-use standards? What is the basis for this? Commenters recommend it be 

deleted: 
Summary of Interagency Working Comments Received on Draft Rule under EO 12866 and EO 13563

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“We believe that as LRR tires become more common on new equipment, the aftermarket prices of

these tires will also decrease. Along with decreasing tire prices, the fuel savings realized through

use of LRR tires will ideally provide enough incentive for owner/operators to continue purchasing

these tires.  The inventory modeling in this final action reflects the continued use of LRR tires

through the life of the vehicle.”

42) Commenters request further clarity on what this means. Please elaborate from page 126 in 

Preamble: 

“The agencies concluded that although laboratory‐to‐laboratory and test machine‐to‐test machine

measurement variability exists, the level observed is not excessive relative to the distribution of

absolute measured RRC performance values and relative to the proposed standards.  Based on this,

the agencies concluded that the test protocol and the proposed standards are reasonable for this

program.”

43) Could EPA describe for the reviewer the process for reviewing and vetting manufacturers’ 

submissions for extra credit under the provision for “innovative technologies?” How will the 

agency make use of public comment? Is there a threshold (in terms of potential GHG 

reductions) for awarding a manufacturer credit for developing an innovative technology? 

This approach, while seemingly well-intentioned, would appear to run the risk of requiring 

an extremely large amount of manufacturer and EPA effort just to determine whether a new 

technological advance qualifies for credit under the program. Is there no simpler way to 

reward technological innovation? 

44) 2. In several subsections throughout Section V, the rule attempts to describe the 

requirements for final reports (pp. 298-299, 317-319, 340-342, 356). The reader found these 

sections confusing because they did not clearly state whether EPA has acceded to 

commenters’ requests to modify the requirements for final reports. Are manufacturers 

allowed to combine EOY and final reports? Or is the NPRM proposal left unchanged? 

Please describe the need for both of these reports, and how manufacturers are supposed to 

comply. 

Also, the subsection “Compliance Reports” and Table V-5 on pp. 356-357 appears to be out 

of place. It could be moved to p. 351, just before Section F on “General Regulatory 

Provisions.” 

45) What is EPA’s current thinking for when and how to update certification and compliance 

testing fees, given the additional demands as a result of this HD and MD trucks GHG 

rulemaking? 
Summary of Interagency Working Comments Received on Draft Rule under EO 12866 and EO 13563

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46) Page 281: In the first sentence of the paragraph that begins with, “Furthermore...” the verb 

is recommended to be “adopted.” 

47) Page 316: The first sentence of the last paragraph could say, “EPA is requiring finalizing

that engines...” 

48) Page 317: The second sentence of the fourth paragraph could say, “These alternative 

standards are defined as 65 percent below...” 

49) Page 341: The first sentence in the third paragraph could say, “One commenter (Volvo) 

requested that the agencies simply simplify the reporting...” 

50) Page 417: The first sentence of the third paragraph could say, “...however, that the gap 

between actual investment in fuel efficiency...” 

51) Page 484: This sentence appears twice in the first paragraph: “The petroleum refinery 

industry employed about 65,000 people in the U.S. in 2009, the most recent year that 

employment estimates are available for this sector.” 

52) Page 489: Commenter suggests removing: “Given job creation as a result of the $1.2 billion 

($2009) in fuel savings...” 

53) Commenter notes that the language in the preamble at p.34 (“Each declaration must be 

submitted in writing to EPA as prescribed in Section V below, and a manufacturer would 

not be considered exempt until EPA and NHTSA have made a formal determination as to 

their status in writing.”) is inconsistent with the plain reading of the text of the rule 

(“Manufacturers meeting the small business criteria specified for “Gasoline Engine and 

Engine Parts Manufacturing” or “Other Engine Equipment Manufacturers” in 13 CFR 

121.201 are not subject to the greenhouse gas emission standards in § 1036.108. Qualifying 

manufacturers must notify the Designated Compliance Officer before importing or 

introducing into U.S. commerce excluded engines. This notification must include a 

description of the manufacturer’s qualification as a small business under 13 CFR 121.201. 

You must label your excluded vehicles with the statement: “THIS ENGINE IS EXCLUDED 

UNDER 40 CFR 1037.150(c).” in order for this exclusion to be valid.”) or language in other 

places in the preamble. This seems not to be a “clarification” but a substantive change to 

the requirements. Interagency commenter recommends allowing the exemption to operate 

by notice. If formal determinations are to be required, commenters recommend that the 

agencies allow exemption by notice to operate while formal determination is pending, and 

the agencies commit to a timeframe for response and a process for appeal to SBA for a 
Summary of Interagency Working Comments Received on Draft Rule under EO 12866 and EO 13563

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determination (since it is an SBA regulation being applied). In any case, interagency 

commenter believes that a single mention of this new requirement is not sufficient notice to 

small businesses, particularly given the number of other places in the preamble and the rule 

where the small business exemption is discussed without mentioning such a requirement. 

54) Interagency commenter also has concerns about the indirect effects of this rule on small 

entities that purchase HD vehicles. Small businesses have asserted that the increase in the 

price of HD vehicles will lead to delays in purchasing replacement vehicles, which would 

reduce the expected benefits of GHG emission standards in any particular year. Logically, 

delay makes sense. Small entities will experience an increase in the immediate purchase 

price. If funded on credit, lenders do not necessarily increase credit availability based on 

future fuel savings. (The analogy is that a bank did not increase the amount it was willing to 

lend someone for a mortgage simply because the homeowner was going to buy a house 

close to the Metro or because the house had double-paned windows.) If self-financed, 

investments would be delayed if on a fixed budget for capital outlays. Only firms large 

enough to have a continuous capital investment cycle will be able to monetize the fuel 

savings and incorporate the fuel savings into their investment stream. In addition, firms 

that buy new and re-sell after a few years can monetize fuel savings through the sale price of 

the used vehicle. Firms that use the vehicle through its useful life don’t have that option. 

Since small firms cannot easily monetize future fuel savings, the increased cost of HD 

vehicles should lead to a reduction in sales. Incorporating this reduction in sales into the 

analysis would reduce the projected benefits of the rule. This is a separate effect from the 

“rebound” effect. There is a further disincentive to purchase new vehicles if they have VSLs 

implemented or have other technologies installed that may limit the useful life or carrying 

load. However, the RIA asserts that there will be an increase in sales. What is the agencies’ 

basis and evidence for claim that rule will increase sales? 

55) Commenter requests supporting analysis for increase in sales. What portion of the costs 

and benefits of this rule are driven by this increase in sales? Have the agencies responded to 

the assertion by independent truckers that fleet turnover will be delayed by this rule? If so, 

please provide specific page numbers? If not, commenter requests clarity on why it is 

missing. 

56) Commenters request clarity on whether the effect of human drivers has been incorporated 

into the expected benefits. Industry and the agencies readily acknowledges that the most 
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effective fuel efficiency technology is driver training, and that a well-trained driver can be 

more fuel efficient than any one of the technologies alone. Presumably, that also means that 

a well-trained driver will be able to use a vehicle in a way that negates the fuel economy 

benefits of this rule in favor of power, speed, or both. Similarly, if a choice of tires can 

improve fuel economy, replacement with a different set of tires will reduce fuel economy. 

Do the agencies incorporate a human factor into their analysis? 

57) Commenter suggests that the agencies clarify in the rule summary when these standards 

apply during the lifetime of HD vehicles. In other words, an explanation that the EPA 

standards apply to both new and “in use” vehicles and how this works. Commenters 

recommend that agencies also clarity on pg. 50 (“What Vehicles Would be Affected?”) 

58) Commenters recommend that Pg. 8 clarify that, while NHTSA’s standard will not cover 

RVs, EPA’s will cover them. 

59) When California is mentioned on pg. 9-10, it would be helpful to provide a quick 

explanation of the fact that California has unique authority to set emission standards. Also, 

if the agencies consulted with other states beside California, it may be worth mentioning this 

outreach here as well. 

60) Pg. 12 – This may be confusing: “While we are deferring action today on setting trailer 

standards, the agencies are committed to moving forward in a timely manner to create a 

complementary regulatory program for trailers.” To the extent possible, the agencies are 

recommended by commenters to clarify what is meant by moving forward on a 

complementary regulatory program for trailers. 

61) Clarifying question: Do the agencies have a timeline in mind for setting standards for 

trailers? Will the industry and other stakeholders be surprised by what seems to be a 

commitment to set trailer standards before the next phase of the national HD program (pgs. 

12 and 500)? 

62) Pages 25-29 summarizing the standards for heavy-duty pickup trucks and vans do not 

include a chart or paragraph that lists the actual standards. For consistency with the sections 

that precede and follow on tractor trailers and vocational vehicles, commenter suggests 

adding this missing piece. 
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63) The summary of costs and benefits (pgs. 35-38) would benefit from greater up-front clarity 

about what is and is not included in the overall estimates of costs and benefits. Also, Table 

I-4 could explain more clearly what is included in “benefits” (why is fuel savings not 

included, for example). Table I-4 is also confusing, because “net benefits” cannot be easily 

derived from the benefit and cost numbers listed within that column. 

64) The summary section on “Program Flexibilities” (beginning on pg 38) does not clearly 

discuss the rule’s provisions that would allow manufacturers to carry forward credit deficits 

(the flip side of banking) and would benefit from additional discussion. Please include this 

discussion. 

65) Pg. 115-116: Commenter suggests revising the explanation for the agency’s selected 

approach to account for FFVs. The current explanation that the light duty program’s 2012-

2015approach is not appropriate because “the HD sector does not have the incentives 

mandated in EISA for light-duty FFVs, and so has not relied on the existence of such credits 

in devising compliance strategies for the early model years of this program” is not 

particularly powerful and is somewhat confusing. Commenters instead recommend that the 

agencies simply explain how the chosen accounting approach demonstrate fuel use and 

associated GHG emissions is logical and benefits low-GHG fuels. 

66) Clarifying questions: Pg. 116 explains that NHTSA will determine fuel consumption of 

dedicated alternative fuel vehicles using the DOE petroleum equivalency factor. How will 

EPA determine GHG emissions of dedicated alt fuel vehicles? Why did NHTSA opt for 

using the PEF rather than methodology similar to the approach used for natural gas vehicles 

(deriving a fuel equivalency based on CO2 emissions)? Does the DOE-derived PEF include 

the 0.15 conversion factor incentive that the agencies reject using for NGVs on pg. 264? 

67) Pg. 264. The discussion of NGVs (first full paragraph on pg. 264) includes a reference to 

FFVs, which seems to be a typo. 

68) The description of early credits (beginning on pg. 265) touches a few times on the concerns 

about providing windfall credits to companies with low baseline emissions/consumption 

levels. Commenter suggests that the agencies explain more clearly and succinctly here why 

the early credit program being finalized will not provide windfall credits. 

69) Clarifying question: Did the agencies do any analysis or rough calculations as the basis for 

concluding that providing a 1.5 multiplier for early credits would generate enough 
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additional early reductions (beyond BAU) to outweigh the loss of GHG/efficiency benefits 

that will be created by adding extra credits to the program? 

70) Pg. 269-270 – On the issue of how electricity-related emissions of EVs should be treated, 

commenters strongly recommend that the agencies include non-tailpipe emissions for the 

purpose of setting standard and for compliance as well. 

At the very least, commenter believes it is important to preserve options for future 

rulemakings and to avoid the impression that EPA/NHTSA have already made up their 

minds about how non-tailpipe emissions should be treated going forward. While the last 

sentence in the paragraph at the top of pg. 270 (“We also recognize that the ongoing 

EPA/NHTSA rulemaking...”) accomplishes this goal, the preceding sentence seems to go 

too far in signaling the agencies inclination to deal only with tailpipe emissions by 

referencing “consistency with past practice...whereby we treat all vehicles equally.” 

Commenter suggest revising this sentence to avoid signaling that any other approach would 

not be viewed as treating all vehicles equally (and to clarify that counting EVs as 0 g/mile is 

to provide an incentive for advanced technologies, which the agencies have said previously 

in the light duty context). 

52) Page 10 (and in RIA where appropriate): commenters provide suggested edits in red: 

“...As in the light-duty vehicle rule establishing CAFE and GHG standards for MYs 2012-2016 

light-duty vehicles, EPA’s and NHTSA’s final standards for the heavy-duty sector are largely 

harmonized with one another due to the close and direct relationship between improving the fuel 

efficiency of these vehicles and reducing their CO2 tailpipe emissions. For all vehicles that 

consume carbon-based fuels, the amount of CO2 emitted from the tailpipe is essentially constant 

per gallon for a given type of fuel that is consumed. The more efficient a heavy-duty truck is in 

completing its work, the lower its environmental impact will be, because the less fuel consumed 

to move cargo a given distance, the less CO2 emitted from the tailpipe into the air. The

technologies available for improving fuel efficiency, and therefore for reducing both CO2

emissions and fuel consumption, are one and the same.[1] Because of this close technical 

relationship, NHTSA and EPA have been able to rely on jointly-developed assumptions, 

                                                           

[1] However, as discussed below, in addition to addressing CO2, the EPA’s final standards also include provisions to 

address other GHGs (nitrous oxide, methane, and air conditioning refrigerant emissions).), as required by the 

Endangerment Finding under the CAA. See Section II. 
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analyses, and analytical conclusions to support the standards and other provisions that NHTSA 

and EPA are adopting under our separate legal authorities. 

The agencies recognize that the ongoing EPA/NHTSA rulemaking to reduce GHGs and fuel 

consumption in MY 2017 and later light-duty vehicles is also further examining this issue, and 

may yield information and policy direction relevant to the planned follow-on rulemaking for the 

heavy-duty sector. The agencies recognize that biofuels, such as biodiesel and ethanol, will play 

an important role in reducing the nation‘s dependence on foreign oil, thereby increasing domestic 

energy security. The agencies recognize that biofuels have unique GHG emission characteristics. 

When considered on a lifecycle basis (including both tailpipe and upstream emissions), the net 

GHG emission impact of individual biofuels can vary significantly from both petroleum-based 

fuels and from one biofuel to another. EPA‘s Renewable Fuel Standard program, as modified by 

EISA, examined these differences in lifecycle emissions in detail. For example, EPA found that 

with respect to aggregate lifecycle emissions including non-tailpipe GHG emissions (such as 

feedstock growth, transportation, fuel production, and land use), lifecycle GHG emissions in 

2022 for biodiesel from soy, using certain advanced production technologies, are about 50 

percent less than diesel from oil. The agencies recognize that in the case of biofuels, ―upstream 

emissions include not only GHG emissions, but also any biological sequestration that takes 

place. For purposes of this discussion, the term ―upstream emissions, when considered in the 

case of biofuels, should be construed to encompass both GHG emissions and sequestration. The 

agencies note that to the extent future policy decisions involve upstream emissions, the agencies 

will need to consider not only upstream emissions from electricity production, but also the 

unique emission characteristics associated with biofuels...” 

53) Page 23: 
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Table I-2: Heavy-duty Combination Tractor EPA TAILPIPE-ONLY Emissions Standards (g 

CO2/ton-mile) and NHTSA Fuel Consumption Standards (gal/1,000 ton-mile) 

54) Page 23: 

“...EPA’s engine-based CO2 standards for tailpipe emissions and NHTSA’s engine-based fuel 

consumption standards are based on EPA’s existing test procedures and regulatory structure for 

criteria pollutant emissions from medium- and heavy-duty engines...” 

55) Page 50: 

“...technologies that would reduce CO2 tailpipe emissions and fuel consumption and that are 

judged to be feasible and appropriate for these vehicles and engines through the 2018 model 

year...” 

56) Page 63: Table II-1, replace “CO2 grams” with Tailpipe CO2 grams” 

57) Page 114: 

“... FFVs, and so has not relied on the existence of such credits in devising compliance strategies 

for the early model years of this program. See 74 FR at 49531. In fact, manufacturers have not 

in the past produced FFV heavy-duty vehicles. On the other hand, we did seek comment on how 

to properly recognize the impact of the use of alternative fuels, and E85 in particular, in HD 

pickups and vans, including the proper accounting for alternative fuel use in FFVs in the real 
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world.[2] See 75 FR at 74198. FFV performance will be determined in the same way as for 

light-duty vehicles, with a 50-50 weighting of alternative and conventional fuel test results 

through MY 2015, and a manufacturer-determined weighting based on estimated fuel use over 

the useful life of the vehicle after MY 2015 (defaulting to an assumption of 100 percent 

conventional fuel use). See 75 FR at 25339. For dedicated alternative fueled vehicles, NHTSA 

will require that vehicles be tested with the alternative fuel, and a petroleum equivalent fuel 

consumption level be calculated based on the Petroleum Equivalency Factor (PEF) that is 

determined by the Department of Energy. 

58) Page 128: Table II-14, replace CO2 emissions with Tailpipe CO2 emissions. 

59) Page 202: Table III-6, replace “CO2 grams” with Tailpipe CO2 grams” 

60) Page 269-270: 

“...The proposal also solicited comment on the handling of upstream GHG emissions. Some 

commenters argued that EPA should maintain its traditional focus in mobile source rulemakings 

on vehicle tailpipe emissions and leave the consideration of GHG emissions from upstream fuel 

production and distribution-related sources such as refineries and powerplants to EPA regulatory 

programs that focus specifically on those sources. Others argued that, since EPA accounts for 

upstream GHG emissions in its benefits assessments, the agency should reflect upstream GHG 

emissions impacts in vehicle compliance values as well. After considering these comments, we 

have decided to maintain consistency with past practice for setting vehicle emissions standards 

under Clean Air Act section 202(a)(1), whereby we treat all vehicles equally, based on tailpipeonly emissions performance. 

                                                           

[2] E85 is a blended fuel consisting of nominally 15 percent gasoline and 85 percent ethanol. 
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We also recognize that the ongoing EPA/NHTSA rulemaking to reduce GHGs and fuel 

consumption in MY 2017 and later light-duty vehicles is also further examining this issue, and 

may yield information and policy direction relevant to the planned follow-on rulemaking for the 

heavy-duty sector.

The agencies also recognize that the ongoing EPA/NHTSA rulemaking to reduce GHGs and fuel 

consumption in MY 2017 and later light-duty vehicles is also further examining this issue, and 

may yield information and policy direction relevant to the planned follow-on rulemaking for the 

heavy-duty sector. The agencies recognize that biofuels, such as biodiesel and ethanol, will play 

an important role in reducing the nation‘s dependence on foreign oil, thereby increasing domestic 

energy security. The agencies recognize that biofuels have unique GHG emission characteristics. 

When considered on a lifecycle basis (including both tailpipe and upstream emissions), the net 

GHG emission impact of individual biofuels can vary significantly from both petroleum-based 

fuels and from one biofuel to another. EPA‘s Renewable Fuel Standard program, as modified by 

EISA, examined these differences in lifecycle emissions in detail. For example, EPA found that 

with respect to aggregate lifecycle emissions including non-tailpipe GHG emissions (such as 

feedstock growth, transportation, fuel production, and land use), lifecycle GHG emissions in 

2022 for biodiesel from soy, using certain advanced production technologies, are about 50 

percent less than diesel from oil. The agencies recognize that in the case of biofuels, ―upstream 

emissions include not only GHG emissions, but also any biological sequestration that takes 

place. For purposes of this discussion, the term ―upstream emissions, when considered in the 

case of biofuels, should be construed to encompass both GHG emissions and sequestration. The 

agencies note that to the extent future policy decisions involve upstream emissions, the agencies 

will need to consider not only upstream emissions from electricity production, but also the 

unique emission characteristics associated with biofuels. 

61) Page 357: 

“...All electric vehicles are deemed to have zero tailpipe emissions of CO2, CH4, and N2O...” 
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62) In summarizing the quantified climate change impacts of the rule on page 377, 

commenter suggests that the agencies provide context about how the HD program 

addresses climate change. 

63) Page 1-39. The document incorrectly describes Plug-in Hybrids as “The third type of HD 

hybrid vehicle is a ‘plug-in’”. Hybrids can be electric or hydraulic as correctly 

mentioned. PHEVs simply mean that the battery can be recharged from a plug. They are 

in fact electric hybrids. 

New DRIA Chapter 1.8 text: 

The third type of HD hybrid design is a ‘plug-in’ which operates on the same principle as 

the electric hybrid only adds the capability to recharge the hybrid battery using an 

external power source. These trucks can use electric power for auxiliary system power 

and operations and can have range-extended batteries as they can switch propulsive 

power to the diesel engine when the battery runs low. Typical applications for this type of 

vehicle include utility (powering the grid), small pickup and delivery trucks, and shuttle 

buses. 

Interagency commenter notes that this section has been removed from the DRIA, and the Table of 

Contents needs to be modified to reflect this. The draft final Regulation (pg 237) has not been 

changed to reflect agency response. 

64) Page 3-9, last paragraph. Commenter recommends that agencies include text to clarify 

that Acceptable uncertainty refers to the reduction in coastdown uncertainty that yielded a 

drag coefficient with approximately 5% standard error. Commenter notes that “achieve 

and acceptable” should be “achieve acceptable”

65) Commenters recommend that agencies include the following clarification in RIA:

For subsequent testing conducted off-site, the following methods were used to develop the 

frontal area. 

• SAE J2263 analysis process requires the vehicle frontal area be measured for each tested 

configuration. 

• The process of measurement evolved through three phases for this program. Early HD 

vehicles were photographed in a parking lot and analyzed using a grid overlay method. 

• In an attempt to improve the process and results, LHD vehicles were photographed in 

front of a “green screen” with a high resolution digital camera with a long telephoto lens. 
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• Finally, all additional HD vehicles were photographed against this green screen 

backdrop, inside of the shop with studio lighting and the camera placement outside in an 

open field on adjacent. (all subsequent vehicles were measured using this method) 

• Photogrammetric computer software was used for the measurements for vehicles 

photographed using the “green screen method.” 

• The contractor sought to largely comply with the methods described in EPA advisory 

Circular No. 73. 

Measurement of the frontal area of a tractor can be considered to be fairly accurate 

because it is based upon simple measurement of tractor geometry. More specifically, the 

area is comprised of a series of length measurements of a static object (i.e. a tractor). 

However, the most important aspect of accurate Cd comparison is the consistent use of 

standard area. This importance arises from the fact that the area is used to convert the 

measured drag forces to a normalized Cd and then used by the simulation to convert the 

Cd back to the drag force experienced by the vehicle. For comparisons of frontal areas, 

accuracy is dependent upon a clear, detailed protocol for which measurements to take. 

Examples can include which components to include (e.g., fender mirrors), factors that 

affect the ride height (e.g., tire inflation), and whether it is based upon the tractor’s 

geometry or a combination of the tractor and trailer geometry (in instances where the 

trailer may extend slightly beyond the dimensions of the tractor).