EPA Hearing- Phase 2 Greenhouse Gas 

Emission Standards for Medium- and 

Heavy-Duty Engines and Vehicles 

rheFirstNameln Trailers August 18, 2015- Long Beach, California 

Utility Trailer Manufacturing Statement 

Jeffrey J. Bennett - Vice President Engineering & 

Development 

Utility Trailer Manufacturing Company appreciates the 

opportunity to comment on EPA's Phase Two Greenhouse Gas 

Emissions proposed trailer regulations. For over 100 years, Utility 

Trailer Manufacturing has manufactured truck trailers; we've grown 

to one of the top three manufacturers by volume in the United 

States. Every day, we strive to improve the standard of living by 

providing high-quality transportation products and other services to 

the transportation industry. Being good stewards of the earth is a 

major part of our mission. 

Utility Trailer and its customers continuously seek to provide 

safe and improved products, services, and efficiencies. Customers 

haul trailers on all types of roads, the rail, and by sea. They must 

perform reliably and safely in extremely harsh, and at times, 

punishing environments. Trailer design has evolved over time in 

these environments, which is why there is great concem abou t the 

proposed EPA GHG-2 trailer regulations. 

The EPA regulations propose to reduce the C02 output of 

trucks by employing aerodynamic devices to long- and short-box 

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trailers. But the EPA's underlying analysis is incomplete in its 

failure to demonstrate how the lifecycle of these aerodynamic 

devices reduces the net carbon footprint. These devices, typically 

constructed from lightweight metal and plastic, require extreme 

heat and significant quantities of petrochemicals to produce. And 

once attached to a trailer, they are unlikely to survive more than a 

fraction of the trailer's expected life. Customers expect our freight 

trailers to last 15 years on average, but these aerodynamic trailer 

devices have only been available since 20 10. Many early-adopter 

fleets report spending over $300,000 per year replacing damaged 

skirts and trailer tails on their long-box trailers. As a result, the 

amount of C02 output to produce and maintain the devices 

proposed by the Agency is still, to this day, unknown, growing, and 

may exceed any aerodynamic savings. 

Currently, the claimed fuel savings for trailer aerodynamic 

devices are significantly overstated. For example, many trailer 

aerodynamic devices, approved by EPA Smartway, that claim to 

provide (5 to lO)o/o fuel savings. But these fuel savings are based on 

overly simplified tests. Some tests, for example, are conducted at a 

constant cruise speed of 65-miles per hour on level roads - not a 

real-world situation. A large, long-haul customer fleet of ours 

measured and recorded the percentage of time that its fleet -

consisting of 4 ,000 trucks and 7,000 long-box trailers - traveled at 

various speeds from 0-mph to 65-mph over the past six months. 

On average, the trucks spent less than 1.3o/o of the time at or above 

65-mph . 20o/o of the time was between 60-65 mph, and 40o/o of the 

Utility Trailer Manufacturing Company Page 2 
time the truck was stopped while the engine was running, waiting 

for traffic, or something else. I've included a graph with my remarks 

showing results for all speeds. This real-world study contradicts 

the speed assumptions that the Agency used in its GEM-2 analysis 

(GEM-2 analysis of 86°/o at 65-mph cruise, 9°/o at 55-mph cruise, 

and 5°/o transient). For a proper fuel-savings estimate, the 

aerodynamic fuel savings measured at each speed must be 

multiplied by the actual percentage of time the truck travels at that 

specific speed and summed to an expected average savings. The 

Agency has failed to provide such a study. In addition, the Agency 

has proposed trailer speeds in their analysis that are dramatically 

greater than what has been measured in the field. 

We have performed a study based on an EPA Smartway 

approved trailer side skirt that measured a 7.5°/o fuel savings per 

the SAE-1321, type-2 modified certification test. Using a CFD 

analysis, the fuel savings was determined at each speed, from 0-

mph to 65-mph. The aerodynamic fuel savings at each speed was 

then multiplied by the actual, measured fleet percentage of time at 

that speed, and summed up to arrive at a total cruising speed fuel 

savings of 1.7°/o across the total measured speed spectrum. This 

total 1. 7o/o savings applies to only the fraction of fuel used for 

cruising at constant speed on flat ground, not for accelerations, and 

not for going uphill. Thus, the total fuel savings is less than 1. 7°/o 

of the total fuel used and not the 7.5o/o claimed by EPA. 

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How can less than a 1. 7°/o of the total expected fuel savings 

justify the C02 output required to manufacture, install, and later 

replace, when damaged, this trailer aerodynamic device? In 

addition, the Agency has neglected the average trailer-to-truck ratio 

in the typical trailer fleet. Several of our customer fleets have two 

trailers for every truck, which doubles the required time and 

required fuel savings for any C02 payback to justify the trailer aero 

device. 

The Agency stated that it intends not to allow any yaw angle 

effects to measure efficiencies from trailer aero devices. From our 

experience from SAE 1321-type track testing, and CFD analysis, 

yaw angle, or cross winds, increase the fuel savings of side skirts 

and decrease fuel savings of trailer tails; therefore, the Agency must 

not ignore the effect of yaw angle on aerodynamic devices. 

The Agency's impact analysis also failed to account for the 

substantial reduction in tire life associated with low-rollingresistance tires and from using tire-inflation systems. Because lowrolling-resistance tires are stiffer, they wear faster due to tire 

scrubbing, curbing, and other wear and tear. Tire inflation systems 

add pressure to inflate tires to a set, optimum pressure. But when 

the tires inevitably heat up, the pressure increases above that 

setting, causing the tires to run overinflated. This rapidly 

deteriorates the tire tread. This increase in tire degradation 

requires more frequent tire replacement, which increases the C02 

output. The Agency has failed to demonstrate how these tires and 

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tire inflation systems will generate sufficient savings to make up for 

the additional C02 released into the atmosphere from additional 

tires needed during the useful life of trailers. 

The GEM model and what the Agency has proposed for 

compliance averaging (bins) would be unmanageable in the trailermanufacturing industry. Trailer orders are comprised of choosing a 

standard trailer base model, standard options, and a quantity. 

Added to these are a large number of special, customer-specific 

options, which can make up approximately 2 I 3 of the trailer 

specifications on a customer order. In addition, numerous changes 

to specification and quantity are made right up to the time we begin 

to build the trailer on the assembly line. Many of the customerrequired options conflict directly with trailer aerodynamic devices, 

tires, and tire-inflation systems. A better approach would be for the 

OEM to pick from a list of EPA approved devices and install those 

on all trailer orders if practicable. 

Utility Trailer manufacturing and its customers welcome any 

technology that truly reduces the total, net C02 output and cost 

associated with the safe, clean, and efficient delivery of goods to 

American consumers. We support EPA's goals but warn against 

regulations that can overstate fuel and C02 reductions and that 

may actually increase C02 output, and without achieving the goal of 

a cleaner, safer, environment. 

Thank you. 

Utility Trailer Manufacturing Company Page 5 
Fuel Savings Study of EPA Smartway Device Across Speed Spectrum: 

Rolling %total % Time 

Cruising Aero Aero Resistance power at Expected 

Speed Aero Power Power Skirt Power Power %Aero (fuel} Specific Savings 

[MPH] Base [KW] [KW] [%]savings [KW} Power Savings Speed at Speed 

0 0.000 0.000 0 0 0 0 39.80% 0.00% 

2.5 0.005 0.005 7.34% 3.125 0.15% 0.011% 2.30% 0.00% 

7.5 0.134 0.124 7.34% 9.375 1.31% 0.096% 2.30% 0.00% 

12.5 0.621 0.575 7.34% 15.625 3.55% 0.261% 1.50% 0.00% 

17.5 1.703 1.578 7.34% 21.875 6.73% 0.494% 1.10% 0.01% 

22.5 3.620 3.354 7.34% 28.125 10.65% 0.782% 1.00% 0.01% 

27.5 6.609 6.124 7.34% 34.375 15.12% 1.110% 1.10% 0.01% 

32.5 10.909 10.108 7.34% 40.625 19.92% 1.462% 1.20% 0.02% 

37.5 16.758 15.528 7.34% 46.875 24.88% 1.826% 1.40% 0.03% 

42.5 24.395 22.604 7.34% 53.125 29.85% 2.191% 2.30% 0.05% 

47.5 34.058 31.558 7.34% 59.375 34.70% 2.547% 1.70% 0.04% 

52.5 45.984 42.609 7.34% 65.625 39.37% 2.889% 4.20% 0.12% 

55.5 54.326 50.339 7.34% 69.375 42.05% 3.086% 3.10% 0.10% 

57.5 60.414 55.980 7.34% 71.875 43.78% 3.213% 4.10% 0.13% 

59.5 66.940 62.027 7.34% 74.375 45.47% 3.338% 10.40% 0.35% 

61.5 73.919 68.494 7.34% 76.875 47.12% 3.458% 19.50% 0.67% 

63.5 81.368 75.396 7.34% 79.375 48.71% 3.575% 1.70% 0.06% 

65.5 89.301 82.747 7.34% 81.875 50.26% 3.689% 1.30% 0.05% 

100.00% 1.65% 

Utility Trailer Manufacturing Company Page 6 
4S.OO% 

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100.000 

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-- 0 ____ 30 __ 40~--

Truck Speed MPH 

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- Aero Power Base (KW) 

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(i) __ __.20 40 

Truck Speed [MPH] 

60 

- Aero Power Skirt [KW] 

Aero Power [%]savings 

go-Rolling Resistance Power [KW} 

% Total (Rolling Resistence & Aero) Power (Fuel) 

Savings 

--------------

-- ~ 

~ 

~- ------- - %total power (fuel) Savings 

0 10 20 30 40 so 60 70 

Truck Speed [MPH] 

Utility Trailer Manufacturing Company Page 7 
Expected Flat Cruising Fuel Savings 

45.00% 

40.00% 

35.00% f30.00% 

"' 

~ 25.00% 

> 

Ill 

V) 20.00% 

Qj 

::I 

u. 15.00% ?{;. 

... 1 

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5.00% 

_...... - '-

0.00% - - 0 20 40 60 -5.00% 

Truck Speed [MPH) 

Flat Grades and No Acceleration 

Utility Trailer Manufacturing Company 

80 

- % Fuel reduction at 

specific speed 

- % Time at Specific 

Speed 

Expected % Fuel 

savings 

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