Heavy-Duty Engine and Vehicle, and 

Nonroad Technical Amendments 

Package

EPA and NHTSA Briefing for OIRA

March 26, 2013

Draft & Deliberative 1
Briefing Outline

• Background of the rule

• Timing of the rule

• Overview of the structure of the rule 

• Elements of the rule

DRAFT & DELIBERATIVE 2
Why are EPA and NHTSA taking this 

joint action now?

• After publication of the heavy-duty GHG and fuel efficiency rule in 2011, EPA and 

NHTSA began an extensive outreach effort to aid in the rule’s implementation.

– Held a series of certification workshops

– Posted Q&A documents on EPA’s Website

• In the course of these efforts, the agencies received a series of comments on 

specific aspects of the rules. In some cases, it became clear that minor changes to 

the rules would help to clarify the rule’s intent, make it more effective, and in 

some cases correct typographical errors. 

• The heavy-duty amendments contained in this rule are based on these 

implementation discussions. 

• EPA is also making technical amendments to a few of the existing highway engine 

and nonroad mobile source regulations based on requests from the regulated 

industry to clarify intent and to streamline the implementation of these standards.

DRAFT & DELIBERATIVE 3
Why is the timing for this rule important?

• EPA and NHTSA HD GHG and fuel efficiency amendments

– Manufacturers need these finalized in mid-2013 for MY13 reports and MY14 

certification

• EPA-only amendments for nonroad & highway engine criteria pollutants

– Nonroad Diesel technical hardship approval amendments - some equipment 

manufacturers need these to continue production in 2013

– Large gasoline engine fuel line permeation test procedure amendment: Compliant lines 

are not available - manufacturers need this to continue production in 2013

– Amendments to existing replacement engine amendments - diesel emission reduction 

act and similar state grant programs need this ASAP to resume suspended clean diesel 

engine replacement programs

– Small gasoline engine certification test fuel amendment - manufactures need this in 

2013 to prevent unnecessary certification testing burden

Draft & Deliberative 4
Overview of this Rule’s Structure

• EPA and NHTSA Direct Final Rule (DFR)/Final Rule (FR)

– Jointly published by EPA and NHTSA

– Only for the Heavy-duty GHG and fuel efficiency amendments

– Some amendments are EPA-only, some NHTSA-only, and some are joint

– Joint DFR/FR maintains a single national program and reinforces the agencies’ 

commitment to joint rulemaking

• EPA-only portion of the DFR

– DFR also contains EPA-only amendments related to highway and nonroad engine 

regulations

• EPA-only Notice of Proposed Rulemaking (NPRM)

– EPA will also publish a parallel NPRM on all of EPA’s DFR contents

• In case of negative comment on any NHTSA portion of the DFR, NHTSA would 

publish a separate NPRM (& FRM)

• EPA and NHTSA would coordinate on any FRM to ensure that a single national 

program was maintained

Draft & Deliberative 5
EPA’s Heavy-Duty GHG Technical 

Amendments

• A detailed list of EPA’s HD GHG technical amendments is 

included in the preamble

– Several typographical fixes

– Certification and test procedure clarifications

– Corrections to make the regulations consistent with the intent 

expressed in the preamble

– Adjust high roof sleeper cab aerodynamic bins to account for a test 

data error discovered after the FRM

• Error has resulted in an unintended significant increase in stringency of the 

standards

• Correcting this error makes the aero bin table’s stringency consistent with the 

stringency we used to determine the costs and benefits of the rule

Draft & Deliberative 6
NHTSA HD Fuel Efficiency Tech 

Amendments

• NHTSA has 14 technical amendments (6 joint with EPA/8 

unique)

– Joint amendments provide clarifications and reduce 

unnecessary burdens

– Unique amendments correct inadvertent misalignments 

with EPA, consistent with the preamble

• Substance: streamline testing and reporting requirements, 

carryover missing EPA provisions on early MY compliance 

and credit holders, align certification options and family 

classifications, fix rounding and typographical errors

Draft & Deliberative 7
EPA-only Replacement Engines 

Revisions

• Engine manufacturers requested changes to address market 

needs and opportunities to reduce emissions with cleaner 

replacement engines.

• On a limited basis, allow highway and nonroad 

equipment/vehicles to upgrade to cleaner new engines that are 

not Tier 4 or HD2010 compliant

– Recent regulation change was interpreted to allow an exemption only 

when the old engine failed prematurely

• Require using cleanest available replacement engines

• Allows for Diesel Emission Reduction Act and similar state clean 

diesel re-powering projects to resume

Draft & Deliberative 8
EPA Nonroad Diesel Tier 4 Technical 

Hardships

• As Tier 4 final standards implementation 

approaches, a few equipment manufacturers 

have said the technical hardship provisions 

are too restrictive to meet their needs

• EPA is amending the Transition Program for 

Equipment Manufacturers to address these 

concerns by allowing for additional hardship 

allowances.

Draft & Deliberative 9
Other EPA Nonroad Amendments

• Allow California gasoline test fuel for Federal nonroad small 

gasoline engine testing

• Revert to original Society of Automotive Engineers (SAE) fuel 

line permeation test procedures for nonroad large gasoline 

engines

– In 2004 SAE updated its fuel line permeation test procedures from 1996, which 

EPA regulations were updated to require

– Manufacturers are not selling fuel lines meeting the 2004 SAE requirement

– Reverting to 1996 procedures is consistent with rule’s intended stringency

Draft & Deliberative 10
Next Steps

• The technical amendments are time sensitive 

for the regulated industries

• The agencies would like to complete 

interagency review as quickly as possible

DRAFT & DELIBERATIVE 11