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### Comments on EPA ' s and NHTSA's Propo sed Greenhouse Gas Emissions and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and VehiclesPhase 2 Siddiq Khan , American Council for an Energy - Efficient Economy (ACEEE) Chica go, ll Hearin g- Augu st 6, 2015 My name is Sidd i q Khan, and I am a se n ior t r a n sportation resea r cher and the heavy-duty vehicle lead at the American Council for an Energy-Efficient Economy (ACEEE). ACEEE, founded in 1980, is a nonprofit organization that acts as a catalyst for energy efficiency policies, programs, technologies, investments, and be h avior. The adoption of the first-ever greenhouse gas emissions and fuel efficiency standards for heavy - duty vehicles and engines in 2011 was a historic step in reducing emissions and oil consumption from the t r ansportation sector. The proposed Phase 2 standards, built on the success of the Phase 1 program, wou l d provide substantial gains in fuel efficiency for heavy duty v e hicles by 2027, provide continu i ty and certa i nty to the manufacturers, deliver savings at the pump to truck owners and operators , and reduce fre i ght costs. The heavy-duty fuel efficiency program i s also a key e l ement of the president's climate action pla n . ACEEE applauds the agencies' excellent work in developing the Phase 2 standards. The proposed rule i mproves upon the existing Phase 1 program in several ways, including:
• Full vehicl e integration. The modeling tool used to calculate vehicles' fue l efficiency {GEM) will become more sophisticated, which will allow many more technologies to contribute to certified fuel efficiency. For example, transmission improvements will register in the vehicle certificat i on process for the first time. The vehicle certification protocols will promote integration of engine, transmission, and vehicle components. ACEEE strongly supports the agencies' proposal that tractor and vocational vehicle man uf acturers be required to chassis test a small n umbe r of veh i cles each year in order to help detect any inconsistencies between emissions reductions simulated in GEM and reductions realized in vehicle op e ration
• Inclusion of trailers. This is crucia l , because known, affordable trailer ae r o and tire technolog i es can deliv e r over 10% fuel savings for tractor-trailers.
• Vocational v e hicle segmentation and re - weighting of test cycles. The addition of vocational vehicle classes will better ref l ect veh ic les' operat in g characteristics. Test cycles will match vehicles' rea l - world duty cycles much better than they do in the Phase 1 program, especially in the case of vocational vehicles, for which an idle cycle has been added. I nclus i o n of ro ad g rad e on the 55- and 65-mph steady-state cycles in Phase 2 willbetter reflect real-world driving. Reweighting operating points for tractor truck engine certification based on real-world data is another positive step. Yet, the proposal can and should be strengthened in several areas to capture more of the available fuel savings and promote greater adoption of advanced technologies. • The standards for diesel engines in tractor applications should be strengthened to provide a strong incentive for manufacturers to make major, sustained investment in engine efficiency technologies over the next 15 years. The proposed 4% improvement in engine efficiency over a decade falls far short of what can be achieved and should be increased to at least 10%. • Gasoline engine efficiency, which would remain unchanged under the proposal, should continue to improve, in order to deliver greater fuel savings and avoid upsetting the gasoline/diesel balance of vocational vehicles. • Fuel efficiency requirements for heavy-duty gasoline pickups and vans should be more consistent with standards for their light-duty counterparts. As proposed, the weightadjusted fuel economy target for a Ford F-250 heavy-duty pickup truck in MY 2025 is 33% lower than the target for a Ford F-150 light-duty truck with similar engine, transmission, and power specs. Such a large discrepancy in fuel efficiency targets for light- and heavy-duty pickups could result in market distortions and cost heavy pickup owners money at the pump. • Consumer fuel efficiency labels, similar to those for cars and light trucks, should be required for heavy-duty pickup trucks and vans. • The Phase 2 standards proposed for 2027 can and should be moved forward to 2024
. Most of the fuel-saving technologies needed for Phase 2 compliance are available in the market today, and the remainder will be available within the next few years. To conclude, ACEEE strongly supports EPA and NHTSA's Phase 2 greenhouse gas and fuel efficiency standards for heavy-duty vehicles and engines. The proposed rule, built on the success of the first phase, represents another important step in the right direction toward managing fuel consumption and greenhouse gas emissions of the heavy-duty sector. We recommend that the agencies strengthen the proposed rule in several areas to ensure that the Phase 2 program achieves maximum economic and environmental benefits

.

### TRB Paper 1 5 -4 977



### F u e l Sav in gs A vail a bl e i n New He a vy -Du ty Truc ks in 2 0 2 5 Siddiq Khan , Ph
. D. 1
, 

### American Council for an Energy

- Efficient Economy (ACEEE) 529 14 1 h 

### Street, N.W. , Washington , DC 20045

1 Corresponding Author 

### Phone : (202) 507-4019 Fax: (202) 429

-2248 Email: skhan @ aceee . org Dave Cooke, Ph.D
. , Union ofConcemed Scientists (UCS) 1825 K Street , NW 8t h floor Washington, DC 20006 Ph o ne : (202) 331-6948 Ema il: dcooke @ ucsusa . org Luke Tonache l Natural Resources Defense Council (NRDC) 40 West 20th Street New York , NY 100 1 1 Phone: (212) 727-4607 Emai l : ltonache l @ nrdc
. org ,

Subm itted Nov 14 , 20 1 4 Word Count: 4 , 778 Table Count: 07 Figure Count: 02 Equiva lent Words: 7,028

### ABSTRACT In 20 I l, the Environmental Protection Agency (EPA) and the National Highway Traffic Safety Administration (NHTSA) adopted the first

- ever fuel efficiency and greenhouse gas emissions standards for medium

- and heavy

- duty veh icles and engines built for the 2014 to 2018 model years . Those standards will benefit trucke rs and consumers and save over a half

- million barrels of oil per day by 2030. The EPA and NHTSA are now working to extend this program beyond 2018
. Large opportunities are now availab le to increase the fuel efficiency of heavy-duty vehicles beyond the technologies needed to meet the 2014 to 2018 standards. We evaluate fuelsaving technologies now ava il able or under development for these vehic les, their engines and transmiss ions. Our analysis shows that , by 2025, these techno log ies could contribute to achieve a reduction of at least 40 percent in average new truck fuel consumpt ion f rom its 20 1 0 levels or by 30 percent beyond the 2011 rule targets . This reduct ion would yield oil savings of 1 .4 million barre ls of oil per day i n 2030. These technologies are also cost-effective
. The payback period for some more specialized truck types will be longer, but average payback will be under two years. 

### Keywords: Heavy-duty vehicles , Fuel efficiency and GHG rule , Emerging Technologies 

### I NTRODUCTI ON The heavy-duty on-road veh icles include vehicles with minimum gross vehicle weight rating (GVWR) of 8 , 500 lbs. to freight trucks with 80,000 l bs. or more GVWR. Three major groups of vehicles represent the heavy-duty sector: Class 2b/ 3 pickups and vans, Class 3-8 vocational vehicles including refuse and delive ry trucks and transit buses, and tractor trucks that are engaged in long and short haul freight movements . In 2013, U.S. highway vehicles consumed 2 1 .5 quadri ll ion British therma l units (Btus) of energy, or about 1 1 .3 million barrels of oil per day (MBD) (EIA 2014) , 28 percent of wh i ch was consumed by heavy-duty vehicles. Heavy-duty vehicle energy use is dominated by large tractor trucks (Class 7 and 8) engaged in moving freight across the country, consuming 66 percent of heavy

- duty energy , 17 percent of total transportation energy and 12 percent of all U.S. oi l consumption (EPA 2011 ). 

### THE 2011 FUEL EFF IC I ENCY AN D GHG EM ISS IO NS RULE The EPA and NHTSA (called 'the agencies' hereafter) adopted the first-ever fuel efficiency and greenhouse gas em issions standards (EPA and NHTSA 201 1 a) for these veh icles in 2011 (termed 'Phase 1' hereafter). The rule covers three major categories of conm1ercial vehicles: heavy-duty pickup trucks and vans (Class 2b and 3); vocational vehicles (Class 2b-8); and tractor trucks (C lass 7 and 8)
. It a lso covers engines used in heavy-duty vocational and tractor trucks. Engine and vehicle manufacturers are the parties to be regulated. Trailers used with tractor trucks are not included
. The agenc i es set standards for C02 emissions and fuel efficiency and also established em ission caps for methane (CH4 ) and nitrous oxide (N 2 0). The EPA program to reduce C0 2 em issions beg ins with model year (MY) 2014 vehicles, while the NHTSA's fuel efficiency program is vo l untary fo r 20 1 4 and 20 1 5 vehicles and becomes mandatory in MY 2016. The Phase 1 standards adopted by both agencies extend to model year 2018 and then remain in effect

2unless ame nded by future rulemakings , such as the post-20 18 " Ph ase 2" s t andards (EPA and N IIT SA 201la). Overall, the Pha se I s tandards requir e about a 16 percent r educt io n in f u e l consumption , on average, from a ll h eavy-duty vehicles
. The rul e h as two-step improvements: the first in MY 2014 and the second in 

### MY 2017. It requires the greatest fuel consumption reduction from tractor trucks , rangin g from 7 to 22 percent in 20 14-20 16 and from 10 to 24 percent in 2017. compared to the 20 I 0 leve l. The range of impro ve m en t s depends on the ph ys ic a l s pecification s of tractor truck s, includin g roof height and cab type, w hich affect the efficacy of aerodynan1ic improvements and anti- idle devices. Vocational ve hicle s will reduce fuel consumption by 4 to 5 p e rcent in 20 14- 2016 and by 6 to 9 percent in 20 17 from the 20 I 0 level. Th ese reductions in cl ud e the requi r ed improveme nt s in engine fue l effic iency. Hea vy-d ut y commercia l pickups a nd vans wi ll reduc e fu e l consumption by 11 percent for gaso lin e fue led tru cks a nd by 16 percent for diesel fueled truck s by 20 1 8 from a comb ined 2010 gaso line/ d iese l ba se lin e. Manufacturers must meet the standards not on a vehicle-by-vehicle basis but on average over vehicles sold in eac h class. These reducti o n s can be achieved u s ing readil y available, "off -th e - s helf' ' tec hn o logies. EPA and N HTSA es tim ated that th e combined standards wou ld reduce C02 e mi ss ions b y about 270 million metric ton s and save about 530 million barrels of o il over th e lif e of mod e l year 2014 to 20 18 ve hicles (EPA 20 I I). The Phase I rul e can be improved in severa l ways. The s trin ge n cy of the rul e was set based on th e assessed capabi lity of individual components. An improv ed approach wou ld conside r the way all compone nt s work together in a full vehicle configuration. For example , th e Pha se I rule failed to consider any tran s mis s ion improv e ments and their pote ntial optimization w ith the engine and red uc ed ve hicl e load. Furthe r , b y not r eg ulating trail ers for tractors , the Ph ase 1 rule mi ssed large fuel sav in g opportunit ies. HEAVY-DUTY VEHICLE PHASE 2 R ULEMAK I NG The agencies are no w working on the next phase of the heavy-duty ve hicl e rul e (White House 2014). While the Pha se 1 regu l ation r e li ed enti re ly on off-th e-she l f technologies that were immediately re a d y to d e ploy, as indicated by the hi g h levels of early certification f rom eng ine manufactmers , many of th e technologie s that are a pplicable by 2025 are s till in the d e m o n s tration phase. H oweve r , manufacturers h ave indicated that technol og ies s uch as waste h eat recove ry, advanced ae rodynamics , and tran s mi ss ion technologie s wh ic h h ave been used in adv anc e d vehicle d e m o n s tration s s uch as th e D epartment of Energ y's Supe r Truck program ( H owden 20 14) , could be brought into the market over the next 5 to I 0 ye ars . These tec hnologies have b ee n identified in analy ses such as the National Re sea rch Co uncil Panel repo11 as app licable in the 2020 tim efra m e (NRC 20 I 0) , and the n ext phase of s tandards can help e n co urage th e ir widespread dep loyment. VEHICLE POPULATIONS AND CHARACTERISTICS To mirror the agencies· process , we ha ve assumed 20 1 0 model year b ase line ve hicles for a ll classes of ve hicl es. We ha ve also grouped th e ve hicle s into the three broad categories id e ntified in the Ph ase I prog ram: Class 7-8 tra cto r-trailers , Class 2b-8 vocat ional ve hicles , and C lass 2b-3 pick-up s and vans. Class7 -8 tractor trail e r s are the biggest fu e l u se r s, consuming
3about two-thirds of tota l heavy -duty fuel consumption, fo ll owed by vocationa l ve hicl es and pickups and vans, consuming 22% and 1 2%, respectively (EPA and N HTSA 20l lb). H owever, because certain technologies may be more or less effective under different operationa l conditions. applicab le to only certain fuels, o r eco nomicall y v iable only in certain applications. we further sub -categorized th ese ve hicl es as appropriate to better quantify the real technological potentia l for reducing fue l consumption from medium

- and heavy -duty vehicl es . 

### Tractor-Trailers In the Phase 1 program , tractor
- trailers are divided into nine categorie s d efined by GYWR (Class 7 or 8) , operation (regiona l or long-haul) , and cab height (low-, medium

- , or highroof cab) as s h own in Table I
. In our work, we have consolidated these nine categories into three: day cabs (shown i n ye ll ow in Tab le I ) , low-roof s l ee per cabs (bl u e), and high-roof s leeper cabs (g reen)
. Thi s conso lid at i on was deemed adequate to capture differences in both duty cycle (regiona l operation of day cabs compared to lo n g-hau l operation of sleeper cabs) and trailers being pull e d (low

- and medium-roof tractors tend to pull n o n- van trailers suc h as flatbeds and tankers. w hil e high-roof tractors wi ll pull almost exclusively box, or van, trailers) while minimi zi n g redundancy in the discussion of t echno log y application and effectiveness. 

### TABL E 1
. Ass um ed sa les fractions of tr ac t o r trailers and con so lidation of c lasses (Source: E P AIN HT SA 2011b). Class 7 (GVW R from 26 , 001 8 (GYWR greater than 33,000 lbs.) to 33,000 lbs.) Cab Sty l e Day S leepe r R oof L ow Med High Low Med High Low Med High Sales Fraction 4 % 0 % 4 % 18 % 0 % 14 % 3 % 9 % 48 %

Note· Day cabs arc s how n in yellow
. Low-roof s leeper cabs are shown in b lue H•g h-roofsleepcr cabs arc show n in green .
To determine the relative populations of these vehicles, we relied upon the new vehicle sales projected in the agencies ' mlemaking for th e 20 1 8 mod e l year (EPA and NHTSA 2011 b). Baselin e fuel eco nomy was also taken directly f r om the age ncies' work. Howev er, for the annua l vehicle miles traveled , we found tha t whi le the agencies ' appraisal of l o n g -haul tractor trailer operation was appropriate (EPA and N HTSA 2011 b), it did not account for the lower annual ve hicle miles tra ve le d (VMT) that wou ld occur during regional operation. Therefore. for day cabs, we derived the annual vehicle mileage through th e Vehicle Inventory and Use Survey (VIUS) , taking the average ann ual mileage for tracto rs w i th a prim ary range of ope ration of less than 200 mi les . (V IUS 2002)
.

4

### V oc a ti o n a l V ehi c l es Vocational vehicles e ncompass a wide assortment of vehicles wi thin many different weight classes, body types , a nd ope ration al cycles. In the agencies' fuel economy and greenhouse gas sta ndard s, vocational vehicles are separate d into three classes , by weight: light heavy-duty (Class 2b-5), medium heav y -duty (Class 6

- 7), and heavy heavy-duty (Class 8). Because th ese categories do not s uffici e ntly de fine a d uty cycle or narrow the app l icab l e technologies in any way , we h ave ignored weight as a d eterm ining factor in our ana lys is
. H oweve r, we do believe that certain techn ologies are only applicable under certain duty cycles. Therefore. we h ave sub-div ided vocational veh icle s into two primary groups ba sed on the applicability of hybrid technologies, which are approp riate primarily for start-stop duty cycles. Though the age ncies have considered bu ses in th e ir assessment of vocational vehicles, we do no t separately co n s ider that ope r at ion becau se it is a small popu lat ion of ve r y specialized vehicles. Current hybrid arch itectures ha ve been demonstrated primarily in four types of veh icl es: refuse trucks. urban delivery trucks , utili ty (o r bucket) tmcks , and transit buses (T IAX 2009). B ecause we have not separately cons id ered transit buses in our ana lys is , we have f ocused on th e delivery, refuse , and uti lity trucks in determining o ur segmentation. According to VIUS 2002, refuse truck s and utility trucks each repre se nte d approximate ly 5 p erce nt of the tota l Class 2b-8 vocational fleet. Step vans , beverage trucks, in su lated refri gerated vans, and other van -typ e trucks repre se nted more than one quarter of Class 2b-8 vocat ional veh icl es. Because this population of vehicles includes a range of duty cycles, from urban stop-and-go to rural/highway hauling , we consider that only halfofthese ve hi c l es would have a duty cycle appropriate to hybrids. This l eads to an approximate division of vocational veh i cles into 5 percent r efuse, 5 percent bucket, 15 perc e nt urban de li very, and 75 p e rcent other. This is like ly an underest imat e of the numb er of vehic les for whic h hybridi za tion could be app l icab le, as a su r vey of California vocational vehicles found that more than halfofthe Class 3-8 vocational veh i cles ran under urban or wo rk- site duty cycles, as opposed to rura l or intercity ope rat ion (Ca ll lEAT 20 13). The agencies identified a baseline fue l economy for the en tire vocational fl eet of9.7 mpg (EPA and NHTSA 2011 b). Ou r ana lysis of the ef ficiency of the 25 percent of vehic les w here hybrids would be appropriate led to an average of 6.0 mpg (T IAX 2009), leav in g the remaining 75 percent with a baseline fue l economy of 12.2 mpg. We assumed 22,087 annual miles for all vocational vehicles that we calculated from VIUS 2002. Our analysis ofVMT across all types of vocational vehicles indicated that their annual VMT varied by vehicle type but in our analysis we assumed a s in gle average figure. Our figure is within the range identified in other r eports (NRC 2010, EPA a nd NHTSA 201 1 b). 

### Pi c k-up s a n d Va n s For C lass 2b

- 3 pick-ups and vans, the Ph ase 1 rule set different standard s for diesel and gaso lin e vehicles. In our analysis, we re tain th at distinction because the engine technologies applicab l e a nd their effectiveness wi ll be ve ry d i fferent for the two powertrain s. As for th e other classes, we determined the total numb er of pick-up s using the agencies proj ected sales for the 2018 model year (EPA and N HT SA 20 It b). The frac ti on of diesel versus gaso lin e pick-ups was d etem1 in ed using the projections from the Energy Inf ormat ion 5

### Adm inistration (E IA 20 14). Baseline efficiencies were taken f rom the agenc ies' ana lys is (E P A and N HT SA 201 1b), accounting for a 20 percent sho rtfall typical of the diff e r

e nc e between th e li ght -dut y combined city/highway test cycle and real world fue l economy. Annual VMT was taken to be the same for all pick-ups and vans, using the average VM T in VIUS 2002 for Class 2b

- 3 pick-up s and vans. 

### ENG INE AND VE HI CLE TECHNO LO GY ASSUMPT IO NS Th e primary r esources used to est im ate technology cost and performance we re EPA and NHTSA · s Pha se l Fina l Reg ulatory Impact Ana lysis (EPA and N H TSA 20 11 b) and Fin a l Rule (EPA and N HTSA 201 l a), th e National Re sea rch Councirs technology assessmen t report (NRC 20 I 0) , th e tec hnology assessment carried out by T IAX LLC (TIAX 2009) in s upport of the NRC report and the DO E Supe r Truck program ( Howd e n 2014). In a few cases, we u se d industry so urc es (Cummins 2013, DTNA 2013, Eaton 2013), as noted be low. While es timatin g th e overall fuel consumption reduction f rom i ndi v idual technologie s, we follow e d the NRC study approac h. Th e N RC Study calculated the percent fuel consumption reduction 

### (% FCR) from packages of efficiency technologie s as follows: 

### % FC Rpackage = 100 [1

- (1

- 

### {% FC Rtechl/100 }) ( I

- {% FCRtec h21100})
.. . {(I

- {% FCRtechN/100} )]
w here 

### % FCRt ec hx is the perc e nt benefit of an indi v idu a l technolog y. This a pproach is , however, conse r va tiv e s in ce b enefits from some of th e t echnologies may b e add itiv e . J n considering whethe r a technology is applicab le to a particular ve hi cle class, it is important to consider w h e ther the techno logy i s eco nomically v iable as well as technolog i cally feasible. Therefore, for each techno lo gy p ac kage , we examined the payback of the package u s ing a d isco unt r ate of 5 percent , wh ic h fa ll s between th e standard discount r ates of 3 percent and 7 p erce nt u se d by the Office of M anagement a nd Budget (OMB 1992)
. Fuel pri ces were assumed to be the 2020 projection s fo r diesel and gaso lin e g iven in An nu a l Energy Outlook 20 13 (E IA 2013) · . Technology cost s were g ive n in man y of the same so urce s as the values for effectiveness. All techn o logy package s included achie vabl e pay back w e ll within the l if e tim e mileage of th e vehicle. 

### Tractor Trailer E ng ine and Vehicles W e assume that engines for tractor trucks will b e equipped with wa s t e heat recovery ( bottoming cycle). Engines will be down s ize d to I 1 

### liters from 14 liters an d w ill operate at II 00- 1300 rpm compared to pre se nt ope ration a t 1400- 1600 rpm. Other engine improvements will include b e tte r air handling and exhau s t gas r eci rculation , dua l-stage tu r bocharging , comb u st ion opt imi za ti o n and imp rovements in selective catalyt ic reduction (SCR), as s hown in Tab le 2. We omitted so me technologi es considere d by the NRC pane l in orde r to avoid double-counting benefit s already counted for the includ ed technologies. Note that we provid e th e minimum and maximum fuel consumption reduction pote ntial for indi v idual technologie s which reflect the vari at io n in fuel sav in gs across vehicle typ es with in the cla ss. 6

### TABLE 2 Engine Technologies for Tractor Trailers % F uel C on s umption R e du ction Technology Du a l- stage turb oc h a r g in g <al Impr oved co m b u sti o n <b> E n g in e fri cti o n r ed u ct i o n (b ) R ed u ced paras i t i c l oa d s (accesso ri es) (bl Aft e rtrea tm e nt im p r ove m e nt (b J En g in e d ow n s i z i ng+ d ow n sp ee din g <c> B o ttom i n g cyc l e <dJ Totab· Min Max 2.5% 5
. 0 % 1
. 0 % 3 .0% 0.5% 2
. 0% 2
. 0% 4.0 % 1 .0% 2.0 % 4
. 0% 4. 0 % 6 .0 % 8.0 % 15.9 % 25.0 % Sources : (a) NRC 20 1 0. (b) E P NN HTSA 20 1 lb : ( c ) DTNA 2013. ( d ) TIAX 2009
Estim a tes of fu e l co n s ump t i o n r e du c ti o n oppo rtuniti es f o r hi g h-roof s leep e r c a b trac tor tru cks a re s h o v,rn in Tabl e 3a
. These improve m en t s y ie ld a redu c t io n in f u e l cons umption o f 4 2

- 50 p e r ce nt fro m 20 I 0 leve ls, o r 23 to 34 p e rce nt f ro m 2 017 ( P os t Ph ase I ) leve l s . H e r e, th e ap pli e d te chnol og ies a rc li g htwe ig ht aluminum w h ee ls on th e tractor , ae ro d y n ami c ski rt s for n o n - b o x trail e r s, a f ull ae r o d y namic pack age includin g boat tail and gap re duce r f o r bo x tr a il e r s, low-ro lli ng resi s tanc e ( LRR) tires on th e tractor a nd traile r , a n ad v an c ed a ut o m a te d manual tran s mi ss ion , and idl e re du c ti o n for s lee p e r ca b s . So me of th e te chn o log ies s hown wilJ b e e mpl oye d b y m anuf ac tur e r s to achi ev e th e Ph ase 

### I s tand ard s; th ese te chn o l og i es will not co ntri b ut e to th e estim a te o f sav in gs b eyo nd 20 17. Trac to r trail e r s o th e r tha n th ose w ith hi g hr oof s lee p e r ca b s h ave s imil a r o p po rtuniti es fo r eng i nes and trans m iss ions and f ewe r re du c ti o n o pp o rtu niti es e l sewh e re, a findin g w hich re fl ec t s a diff e r

e nt du ty cycle fo r th ese ve hicle s . We ca lc ul ate th a t f ue l co n s um p ti o n o f low - a nd mid

- roof s l ee p e r cab s can b e re du ce d b y 3 8 to 4 7 p e rcen t relati ve to 20 I 0 (Tabl e 3 b). Fu e l co n s umpti o n o f d a y cab tr ac to r tru c k s c an b e r e du ce d by 35 to 42 p e rce nt fro m 2 0 I 0 le vel or b y 2 1 to 33 p e rce nt from 2017 leve ls (Tabl e 3c). ln o rd e r to es tim ate s a v in gs pot e nti a l fro m tra c to r-trailer s a s a w h o l e, we multiplied th e f ue l sav ings potenti a l of hi g h- , mid- , and low roo f s l ee p e r ca bs by th e ir res p ec ti ve m arket s h a r es. 

### TABLE 3a Technology Package for Hi g h Roof Sleeper Ca b Tractor Trucks 

### % Fue l Co n s umption Reduction Technology En g in e improve m e nt <a> Tran s mi ss ion (b) Trac tor Ae r o d y n a mic s (b) Tra il e r Ae ro d y n a mi cs (x 3) (b) LRR T ires ( i nc ludin g tra il e r x 3) < b

> A luminum w h ee ls ( trac tor ) (c) Idl e R e du c ti o n ( b ) 

### Totals
7 

### Min Max 15
. 9 % 2 5.0 %

7.0 % 7.0 % 3 .0 % 4.0 % 8. 3% 8 .3% 1 1. 0% 11. 0%

1. 0% 1 .0% 5 .0 % 8. 0% 

### 41.8 % 50.2 %(a) Tab l e 1 : (b) NRC 2010. (c) EPAIN HTSA 20 11b 

### TABLE 3 b Tec hn o logy P a ckage for Low! Mid Ro of S lee p er C a b T r ac t o r T ru ck s % 

### Fu el Co n s umpti o n R educ t i o n Tec hn o logy En g ine improvement ( a) 

### Transmission ( b) 

### T ractor Aerodynamics ( b ) 

### T rail er Aerodynam ics (x 3) (b ) 

### LRR T ires ( in cl ud in g trail e r x 3) tbl 

### A lumi n um w hee l s (trac t o r ) (c) 

### I d le R educ ti o n ( b ) 

### To tal s (a ) Table 1 : (b) NRC 20 10. (c) EPAIN II TSA 201 1 b 

### M in Max 15.9% 25
. 0% 7.0% 7.0% 2
. 0% 2.0% 3.5% 3.5% 11. 0% 1 1.0 %

1
. 0 % 1
. 0 % 5.0% 8
. 0% 38. 1 % 46.5 %



### TAB LE 3c Tec hn o lo gy Packa ge fo r Da y Ca b Trac to r T ru cks 

### % F u el Co n s umption R edu cti on T echn o logy Eng ine i mprovement ( a) 

### Transmission < b

> 

### Tractor Aerodynamics ( b) 

### Trailer Ae rodynamics (x 3) ( b) 

### LRR Tires (incl udi ng trailer x 3) < b

l 

### A lu mi n um whee l s ( trac to r) (c) 

### T

o tal s ( a ) Tabl e 1 : ( b ) N R C 20 10 : (c) E P AIN H T SA 2 0 11 b 

### M in Max 1 5.9% 25
. 0% 7.0% 7.0% 2.0% 2.0% 3.6% 3.6 % 1 1 .0% 1 1 .0%

1 .0% 1
. 0% 34. 9 % 41. 9 %



### In add it ion to the technologies identi fi ed above , furthe r tec hn ology advances are anticipated for tractor traile rs i n the P hase 2 timeframe , though they may not be employed fully across the fleet. T hese improveme nts in clude m ore advanced trailer aerodynamic packages (NRC 20 1 0) , d u a l- clu t ch automated man u a l transmiss io n s (Eaton 20 1 3) , 6 x 2 dri ve ax les (NACFE 20 1 4), ve hi c le spee d limite rs (E PA a nd NHTSA 20 1 0b) , Eco t r ans mi ss ions ( i .e. tra n s mi ss io n gear a t ne utra l w h il e c ru is in g a t d ow nh ill ), a nd b o th lo ng -h a u l ( TI AX 2 00 9) a nd short- h a ul (NREL 20 12) hyb ri d ization . W e h ave assu m e d in our fi n al res ul ts (Ta b le 5) addi tional improveme nt s f rom th ese tec hn o l ogies of 5.5% o r hi g he r for hig h-r oof s leepe r cabs and 1 .4% o r more for bo th low- roof s leepe r cabs and day cab s, well be low the levels of improve m ent that would be achieved w i th w id e s pread ap pli cat ion ofthe s e technolog ies.



### 8

### Vocationa l Veh icl e E n g in e and Vehicles TABLE 4 Techno l ogy Package for Vocationa l Vehicles 

### % Fue l Cons u mption Reduction T e chno lo gy Impro ve d combust io n (a) Turbocharger s impro veme nt ( a ) Ef ficienc y in ai r-handling (a) Low-temp ex h a u st gas recirculation (a) Engin e friction r e duction (a) Electrification of accesso rie s <a) Hybridi zation (b) Transmission (c) Tires and w hee l s (b) Cab aerod y nami cs ( d J 

### Totals t (a) EPAINIITS A 20 10b. (h) 1\'RC 2010. (c ) Eaton 2013: (dl TIAX 2009 

### Min Max 1.0 % 3
. 0% 1.0 % 2.0% 1.0 % 1.0 % 1. 0% 2.0% 1.0 % 2.0% 2.0% 4.0% 30
. 0% 40.0%

8.0 % 10.0 % 2.0% 4.0% 5.0% 8.0% 22.8 % 33
. 2 %

t Includes 25°o pcnctmt 1 o n of h y bnds and 10•• penetrati o n of cab acro<:l) nam ics
T ec hnol ogy est im ates for vocationa l ve hicl es a re presented in Tabl e 4. For vocat ion a l vehicles, we conside re d o nly diesel engine s for s implicity. H oweve r , as n ote d in the pick-up tru ck sect ion below, gaso lin e eng in es would lik e ly res ult in s imil ar level s of impro ve ment. We h ave largely considered a s imilar suite of techn o log ies for the vocation a l di ese l eng ines that we did for the tractor-trail e rs; howe ve r, becau se th e duty cycles are m o re diverse and result in s ig nificantl y more transient operat ion . waste heat r ecove ry was not considered for v ocational vehicles
. The si n gle b igges t potentia l area of reduction in fue l co n s umpti o n comes fro m the adoption of parallel hyb rid powertrains in utility tru c k s, ref u se tru c k s, and box trucks. As d esc ribed above , this t ec hnology is only applicab le to those veh icl es with th e most start
- stop inten se duty cycle s a nd was therefore applied to just 25 percent of the vocational fl ee t. Si milarl y, aerodynamic improv e ments would o nl y r es ult in substantial fu e l sav in gs for tho se ve hicle s that tra ve l predominantly at high speeds and we re therefore only app li e d to 10 percent of the Oeet. 

### H eavy- D u ty Picku p T r ucks and Vans Our ana lysis foc u se d o n complete pickup s and vans, which constitute more than 90 p e r ce nt of Class 2b-3 ve hicl es, according to the Pha se 

### I rule (EPA and N HT SA 20 1la). The incomplete pickup s are e ither w ith out the primary load carrying device or n o conta in er being a tt ac hed (E PA and NI-IT SA 20 11 a). The majority of th e improvement projected for these ve hi cles w ill come from e ng ine and tran s mi ss io n and accessory electrification. These fuel consumption r e duction estimates are based on turbocharging and down s iz in g for gasol in e e ngines and 42V start-stop sys tems with regen e rativ e braking for both gasoline and diesel. Use
9

### o f fu ll hy brid techn o logy for th ese vehicl es could brin g an addition a l 1 3 to 1 4 p e r c ent fuel sav in gs, b ut we did no t in c lud e h ybr i d i zati o n du e to it s re lat i ve ly h ig h cos t.



### OV E RALL F UE L C ON S UMPTION REDU C TIONS I N PHASE 1 AND PHASE 2 TABL E 5 C o s t-E ff ecti ve Fu el S avin g I mprov ements acro ss Veh i c le Categories % F ue l S h a r e o f B ase lin e 202 5 Co n s umpti o n Pay b ac k Tru c k C la ss Ve hi c le s MP G MPG R e du c tio n

**nth s2**  S le ep e r C ab ( hi g h) T rac t o r-T ra i ler 50 % 5
. 8 1 1.4 49 .\ % 13 S le e pe r Cab ( lo w) T ractor-Tra il e r 13% 5.8 10. 2 4 3
. 3% 10

**Da ~**  C ab T rac tor-T ra i l e r 37 % 5
. 8 9
. 6 39 .4 % 1 7 Tra c tor- Traile rs 5.8 10 .7 -15.9 % 1 3
Hybrid Vocat i o na l Ve h ic le s 25 % 6.0 1 1.7 48.6 % 54

**No n-H**  **br d**  Vocat io na l Ve hi c l es 75 % 12
. 2 15.5 2 1. 3 % 39 Vo c atio nal V e hicles 9. 7 1-1
. 3 32.3 % -1 8
H

e a vy -Duty P ic k

- up /V an (ga s o lin e ) 45% 1 2
. 3 1 7 .4 2 9.4 % 4 7

**ea Dul**  **J:** Pi ck -u e!V an { di ese l ) 55 % 10.5 14 .3 26
. 3 % 26 He avy-D u ty Pick

- u p

/ Vans 11 .3 15.5 2 7 .6

% 35
Tot a l Fu e l Co n s ump t io n R e du c ti o n 4 0.6 % 23


### Tab le 5 s umm ari zes the e fficiency improve me nt s, oi l sav in gs, and eco no m ic payback f o r th e te clmo log ie s d esc rib e d abov e . Fo r thi s s um mary, the midp oi nt va lues of the a s se s sed r an ge of improveme nt s we re ass um e d , r ep rese n ting a s o m e w h at conservat ive es ti m a te of th e effect i ve ness o f a comb in a tio n of t ec hno log ies. T he tec hn o log ies t o improve fu e l e ffi c i e ncy a r e c o s t
- e ff ec ti ve. Fo r exampl e , a new trac to r-tr ailer th a t in c lud e s an a d v ance d e ng in e a nd tran s mi ss i o n , new ax le de s ig n , a nd impro ved ae rody n ami cs t o th e tr acto r a nd tra i ler could save . o n ave rage, ab o ut $3 0 ,000 p e r ye ar in fu e l. U nd e r co n se r v at ive a s s umpti o n s of 10 3, 1 3 0 ave rage a nnu al m i le s f o r a ll trac to r typ es and $3

. 6 5 p e r g allon of di ese l f ue l i n 2 0 2 5 , the se ne w e ff i c i e ncy te chnolog ies w o u ld in c rease tru ck p urc h as e co s t s b y ab o ut $32 , 000, w hi c h i s r e cov e r e d by f ue l sav in g s in j u s t 1 3 month s .

1 0450

400

"t:l .S! 350 Cll :> ro 

## ... 1- 

### "' .S! 300

**~** Cll u



### ~ 250 >
200

150 2010 

## Heavy-Duty Truck Miles

2015 2020 2025 

### F I GURE I: 

### Dome s ti c Tru ck Use Expected to 

### R i se 2030 2035

A s more ef ficient new veh icle s re pl ace o ld er s tock in th e on-road fl ee t , th e total fle e t fuel con s umption and g ree nhou se gas e mis sions a re reduced. In 20 13. the o n-road truck fleet con s um ed about 2 .7 million barrels of oil-derived fuel s p e r d ay and was r es p ons i ble for emitting 530 milli o n m e tri c ton s of g r ee nhouse ga s e mi ss ion s. ln the coming yea r s, the d ema nd for good s shipped by truck i s projected to increa se (E IA 20 13 ), res ulting in more truck

- mil es (Fi g ure 

### 1). H oweve r , a strong seco nd ph ase of standard s- which co uld achieve a 40 perc e nt reduction f rom new trucks b y 2025 co mpared to 20 I 0 leve l s-w ould reduce fu e l co n s umed by th e e ntire onroad tru ck fle e t to below today 's leve ls as s h ow n in Fi gu r e 2
. Usi n g th e A r gonne Nat ional Labo ra tory VISION mod e l (J\N L 20 1 3) ca librated to E IA Ann u a l E n e rgy Outlook 20 13 , we es timate that by 203 0 , the combinatio n of both pha ses of s tandard s cou ld cut fuel use by 1 .4 million barre ls p e r day and redu ce carbon p o lluti on b y 270 mill i o n m e tric ton s a nnu a lly
.

II> 

## "' c 4.5

4.0



## ... Q) Q. :: 3.5 0 0 

### "' Qj t:

**~** 3
.0 c 

## §

**~**



## 2.5 **~**

2
.02010 2015 2020 2025 2030

_._ With 2010 Fue I Efficiency _._ Phase 1 Standards -o- Phase 2 Opportunities 2035



### FIGURE 2: T ru c k Sta nd a rd s R e du ce T ota l O n-Roa d F lee t F uel Co n s umpti o n



### FEE DB AC K AN D COMMEN T S FRO M S TAKE HO LD ERS W e pre se nted thi s ana lys i s to multiple s takehold e rs, includin g e ngine a nd ve hicle m a nu fac turer s , e quipm e nt s uppliers , r egulatory ag e nci es and environmental g r oups. We ha ve sha re d o ur as s umption s a nd ca lcu lation m e thod s w ith th e m. Whi le the fuel sav in gs est i m ates f or in divid ual tec hn o log ies were fam iliar to th e heavy -duty communi t y. so me c la rification s were nee ded to spec if y test cycle s o n which th ese e ffici e n cy numb ers we re ge nerated. So me of th e fue l e fficiency numb ers we re ge ne rat e d o n U.S
. E P A rampe d modal cycle (RMC) and may n o t b e realize d i n re al-world operation. How e ver , our numb e rs are t a ke n mo s tly f ro m the m id-ra n ge, and thu s do n o t c la im th e full potential b e ne fit of th ese tec hnol og ies . Question s were al so asked on th e tec hn o l ogy penetrati o n ra t e, especially on hybrid ve hicl es, was t e heat r ecove r y, and tr a n s mi ss ion improvement. If th e s tand ard s a re set con s id e ring th ese fu e l effic ie nt tec hn o log ies th at provide rea so nable p aybac k , p e netration w ill take place soo ne r rather th an la te r in our assessme nt. In ge ne ral , w e r ece ived p os iti ve res pon ses fr o m th e majority of stake holder s. For , exa mpl e, Cummin s In c. , a maj or heav y- dut y eng in e m a nufacturer , ha s pro v id ed s imilar e n g in e impro ve m ent projection s for th e nex t d ecade (C ummin s 20 14)
.

12

### CONCLUSION Building on the foundation laid in the first round of fuel economy and greenhouse gas emissions standards for medium

- and heavy-duty v e hicl es, a seco n d p h ase of standa rds cou ld achieve more th an 40 perc ent fuel sav in gs from th e average new heavy-duty vehicle in 2025, compared to 20 10. N um erous technologies have been identified that can be d eployed in this timeframe to achieve these s igni ficant reductions in o il co n sumpt ion, r ed ucin g the climate impacts ofthe medium- and heavy -duty tl ee t to 20 1 0 leve ls de s pite inc reasi n g activity in th e f r e ig ht sec tor. Addi ti onal technologies will become avai lable over the tim e period di scussed here. Far greater tractor-trailer drag r educt ions appear to be po ssib le. Aerodynamic impro ve m ent with th e accompa n yi n g e ngine op timization co uld b ri n g major furth er efficie n cy gain s . Fu ll hyb rid systems , once costs b eg in to decline, could ac hi eve a high level of pene tr ation in bot h th e vocational and heavy-duty pickup seg m ents. The adoption of such technologies wou ld add subs t an ti a ll y to the sav i ngs shown here. In that sense, th e fue l efficiency impro ve m ents discussed above a r e m erely a fir st step in defining an a mbitiou s, achievab le t a rget for fu e l effic iency improvements in the heavy-d uty veh icle sec to r. 

### REFERENCES ANL (20 1 3) Argon n e Nationa l Laboratory, ·"The Vis ion Mode l. " http : //www .transportation.anl.gov/ modeli ng simul at ionNl S ION/. Ca l H EA T (20 13), Research and Market Transformation Roadmap to 2020 for Medium- and He avy -Dut y Vehicles. C ummin s (20 1 3), C ummin s p r ese ntation to Enviro nm e nt Group, Co lumbus, IN, dated April 15
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erg ing Technolog i es fo r H eavy Dut y Vehic l e Fue l Efficiency , Wash ington DC, Jul y 22, 20 1 4. DTNA (20 1 3), Progress and Overview of DTNA SuperTruck Proj ec t , Pr esented at SAE Government/lndustry Meetin g, J a nu a ry 20 1 3. Ava il able a t http : / / www . sae.org/ events/ gim / presentation s/20 13 / rotz de rek.pdf Eaton (20 13) , EPA G HG- Ph ase 2 D iscussio n w ith Enviromnent Groups , Washington DC , May 8-9,20 1 3 EIA (20 13) , Annua l Energy Outlook 2013 , U.S. Energy In format io n Adm ini s tr at ion, 20 1 3 E IA (2014), Annual Ene rgy Outlook 2014, U.S. E n ergy Informati on Ad mini stration, 2014. E P A 20 II , Regulatory Annou n cement , Offic e of Tran s portation and A ir Quality. E PA-420-f1 1 -032. August, 20 II.

1 3

### EPA and NHTSA (20 11 a), Greenho u se Gas Emissions Standards and Fuel E fficiency Standards for Mediun1- and H eavy -Duty E ngin e and V e hicl es; Fin al Rul es, Fed e r al Regi s te r, Vol. 76 , No. 179 , September 1 5, 20 11. EPA and N HT SA (20 11 b ), Reg ulatory Impact Analysis {RI A), Fin a l Rul emak in g t o Estab li s h Gree nhou se Gas Em iss ion s Standards and Fuel Effic ie ncy S tandard s for Medium- an d Heavy Duty En g ine and Ve hi c les, U.S. Env iro nm e ntal Protec tio n Agency and Nat io n a l Highway Traffic Safety Admi ni stration, E PA

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content/uploads/20 14 / 0 l/Trucking

-Ef:ficiency

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- Cola Refrestlli1ents Class 8 Di ese l E lectric H yb rid Tractor Ev alu a tion: 1 3-Mo nth F in a l Report. Pr e par ed und e r Task No. FC08.3000 by K. Walkowic z, M. Lammert , and P. C urran. NREL/T P-54 00-5 3502. August 20 1 2. Available on lin e at http ://www . nrel.gov/ docs / fy12osti / 53502
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- and Heavy Duty Vehicles, Final Repo rt. Report to th e Nati ona l Academy of Sciences, September 2009. White H ouse (20 14) , The White House, F act She e t , Opportunity For A ll : Improving the Fuel Efficiency of American Truck s- B o ls t e ring Energ y Security. Cutting Carbon Po llut ion, Sav in g Money a nd Supporting Manufacturing Innovat io n , R e lease d o n February 18 , 20 14 V IUS (2002), Ve hi cle Inventory and Use Survey ( Di sco ntinued). U.S. Census B ureau .

14