STATEMENT OF THE 

MANUFACTURERS OF EMISSION CONTROLS ASSOCIATION 

ON THE ENVIRONMENTAL PROTECTION AGENCY'S PROPOSAL: 

GREENHOUSE GAS EMISSIONS STANDARDS AND FUEL EFFICIENCY 

STANDARDS FOR MEDIUM- AND HEAVY-DUTY ENGINES AND VEffiCLESPBASE2 

August 18,2015 

Good afternoon, I am Dr. Rasto Brezny, the Deputy Director of the Manufacturers of 

Emission Controls Association. MECA is pleased to provide comments in support of the U.S. 

EPA's proposed rulemaking to establish medium- and heavy-duty greenhouse gas emission 

standards and corporate average fuel economy standards for model years 2018 and beyond. 

MECA is a non-profit association ofthe world's leading manufacturers of emission 

control technology for mobile sources. Since the list of regulated pollutants has been broadened 

to include C02, the portfolio of products offered by our members has also expanded beyond 

exhaust catalysts and filters to include technologies that impact combustion efficiency and 

improve the overall C02 emissions of the powertrain. 

We will submit detailed written comments, however, today I would like to focus on a few 

specific aspects ofEPA's Phase 2 proposal: 

l. MECA strongly supports the continued use of separate engine and vehicle standards. 

This framework, established under the Phase 1 heavy-duty standards, ensures the 

important testing linkage between engine criteria and greenhouse gas emissions, and 

ensures that manufacturers deliver durable, enforceable improvements to truck fuel 

efficiency. 

2. MECA believes that cost effective technical solutions will be available to allow for 

the faster 2024 implementation timeline included under Alternative 4 in EPA's 

proposal. Manufacturers need this regulatory clarity to continue to make investments 

in technologies that will deliver the target reductions. 

3. MECA supports EPA's proposal to lower the cap on N20 emissions by 50%. This 

tighter N20 cap at 50 mglbhp-hr will be challenging in the expected future of lower 

exhaust temperatures associated with improved engine efficiencies but manufacturers 

have a number of technical opportunities available to them to keep N20 emissions at 

low levels, including improved catalyst formulations, ammonia slip catalysts with 

high selectivity for nitrogen formation, and efficient urea dosing strategies. 

4. MECA supports EPA's proposal to close the current emissions loophole on truck 

glider kits. It's time to insure that all new trucks utilize the clean diesel engine 

options that have been available since 2010. MECA asks EPA to consider an earlier 

implementation date for this glider truck provision instead of waiting until 2018. 
5. MECA believes that PM emissions from auxiliary power units should be controlled 

through the application of proven diesel particulate filter technology. There are 

already examples of small off-road diesel engines engineered with filter solutions that 

include active regeneration. EPA should follow California's lead and implement 

policies so that APU engines can benefit from the use of cost effective filter solutions. 

Finally, MECA believes that further reductions in NOx emissions from new heavy-duty 

on-road diesel engines, beyond the 2010 highway requirements, will be possible through the 

combination of advanced diesel engines and evolutionary improvements to the existing suite of 

diesel exhaust emission control technologies. Clean diesel emission technologies and 

calibrations have evolved and matured since EPA finalized their heavy-duty 2007-2010 emission 

standards nearly 15 years ago. The current technologies will continue to advance by including 

high cell density, low thermal mass substrates, improved SCR catalysts coated directly on 

particulate filters, and next generation oxidation catalysts that include low temperature passive 

NOx adsorber capabilities. The application ofSCR technology on diesel engines has allowed 

engine manufacturers to optimize for both low NOx emissions and improved fuel efficiency and 

we believe that these optimizations can continue in the future to further reduce both C02 and 

NOx emissions. 

Advanced diesel emission control technologies are currently being evaluated in a 

California-sponsored test program to demonstrate the ability to meet a 0.02 g/bhp-hr NOx 

standard without negatively impacting C02 emissions. The diesel emission control technologies 

being demonstrated in this program are focused on delivering NOx reductions during the cold 

transient portion of the test cycle and on improving NOx emissions performance in low 

temperature duty-cycle operations. These technologies will in tum facilitate the reduction of 

C02 emissions from vehicles by extending the calibration window available to optimize 

combustion efficiency over lower temperatures. 

Furthermore, reduced NOx emissions from heavy-duty engines will provide important 

cost-effective reductions for regions of the country with current and future ozone non-attainment 

issues. A MECA sponsored modeling study, using MOVES2014, estimated the NOx reduction 

benefits of a national 0.02 g/bhp-hr federal heavy-duty NOx standard. When fully implemented, 

such a program would deliver 266,000 tons per year or 730 tons per day ofNOx reductions 

across the 4 7 contiguous states outside of California. 

MECA asks EPA to initiate a rulemaking that will further reduce NOx emissions from heavyduty engines as soon as possible to allow the industry to develop fully optimized future engines 

that deliver improved fuel efficiency and ultra-low NOx emissions. 

CONTACT: Rasto Brezny, Deputy Director MECA, E-mail: rbrezny@meca.org 

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