Summary	of	Interagency	Working	Comments	on	Draft	Language	under									

E.O.	13563	and	12866	Interagency	Review.		Subject	to	Further	Policy	Review.

Comments on U.S. Environmental Protection Agency Proposed Rule, “Control of Air Pollution from Motor Vehicles: 

Tier 3 Motor Vehicle Emission and Fuel Standards,” RIN 2060-AQ86

1) Gauging fuel consumption impacts - Suggest EPA assess the overall change to fuel economy within vehicle 

category. Did the State of California conduct a similar analysis in support of its LEV III rulemaking? If so, 

suggest incorporating by reference, since this proposal discusses essentially the same 

vehicle/technology/stringency combinations.

a. How much will the high oxygen content of the new fuel affect fuel consumption? The new certification 

fuel means a priori lower fuel economy than that of the higher energy-density current certification fuel. 

b. What additional exhaust control equipment weight will be added to achieve the new emissions limits

and what will be the fuel economy penalty be compared to the baseline? 

2) Refinery compliance costs and sulfur disposal 

a. What assumptions has EPA made concerning the by-product use of the sulfur removed from the 

refinery process? Elemental sulfur market remains relatively soft, so refiners may be tempted to back 

the sulfur down to heavier refined grades (a common practice over time) rather than extract it. 

b. Is the only feasible receptacle for this heating oil? As the recent stringent limits on hoteling emissions 

in U.S. ports and sulfur control for nonroad diesel have essentially eliminated bunker fuel, the old 

standby of bygone days, and “red” diesel as candidates. How did EPA consider the opportunity costs of 

not being able to use the higher sulfur fuel in these previously available markets? Please describe the 

assumptions used, relative differences in value of products, and markets where EPA expects these 

products to now be used. 

c. With respect to increased stringency of gasoline sulfur limits, refiners were already producing or 

preparing to produce ultra-low sulfur gasoline for the California market; however, this sulfur reduction 

will not be without added cost in order to comply nationwide. 

3) In what respects is the Tier 3 rule not aligned with the CARB LEV III rule? 

a. Will auto manufacturers be required to perform additional test procedures for the Tier 3 rule, that are 

not required under LEV III? If so, what are the costs to auto manufacturers of purchasing the 

equipment and/or running the tests that are required under Tier 3 but not required under LEV III?

4) How does EPA account for the increased costs to manufacturers and consumers for repairing emissions control 

systems? As manufacturers are forced to add more intricate technologies to achieve more stringent emissions 

standards, the likelihood and frequency of problems that would require repair would presumably increase as 

well. Where does EPA address this issue in the rule?
Summary	of	Interagency	Working	Comments	on	Draft	Language	under									

E.O.	13563	and	12866	Interagency	Review.		Subject	to	Further	Policy	Review.

5) Certification fuel revisions – Will EPA explain the rationale for the proposed change to the specifications of 

vehicle emission/fuel economy certification fuel? The table below highlights key changes to the certification 

fuel specs:

Proposed Gasoline Emissions Test Fuel

Property Unit

SPECIFICATION

ASTM Reference 

Procedure General

Testing

LowTemperature 

Testing

High Altitude 

Testing

Antiknock Index 

(R+M)/2 - 87.0 - 88.4

87.0 

Minimum D2699-11 and D2700-11

Sensitivity (R-M) - 7.5 Minimum

Dry Vapor Pressure 

Equivalent (DVPE)

kPa (psi) 60.0-63.4

(8.7-9.2)

77.2-81.4 

(11.2-11.8)

52.4-55.2

(7.6-8.0)

D5191-10b

Distillation

10% evaporated

°C (°F) 49-60

(120-140)

43-54

(110-130)

49-60

(120-140)

D86-10a

50% evaporated °C (°F) 77-88 (170-190)

90% evaporated °C (°F) 154-166 (310-330)

Evaporated final 

boiling point

°C (°F) 193-216 (380-420)

Residue Milliliter 2.0 Maximum

Total Aromatic 

Hydrocarbons

vol. % 19.5-24.5

D5769-10

C6 Aromatics 

(benzene) vol. % 0.6-0.8

C7 Aromatics 

(toluene) vol. % 4.4-5.5

C8 Aromatics vol. % 5.5-6.9

C9 Aromatics vol. % 5.0-6.2

C10+ Aromatics vol. % 4.0-5.0

Olefins mass % 4.5-11.5 D6550-10

Ethanol vol. % 14.6-15.0

D5599-00 (Reapproved 

2010)

Total Content of 

Oxygenates Other 

than Ethanol

vol. % 0.1 Maximum
Summary	of	Interagency	Working	Comments	on	Draft	Language	under									

E.O.	13563	and	12866	Interagency	Review.		Subject	to	Further	Policy	Review.

Sulfur mg/kg 8.0-11.0

D2622-10, D5453-09 or 

D7039-07

Lead g/liter 0.0026 Maximum D3237-06

Phosphorus g/liter 0.0013 Maximum D3231-11

Copper Corrosion - No. 1 Maximum D130-10

Solvent-Washed 

Gum Content

mg/100 ml 3.0 Maximum D381-09

Oxidation Stability Minute 1,000 Minimum D525-05

6) Ethanol by % volume - Will EPA explain the rationale for jumping from the expected choice of a 10%-by-volume 

ethanol fuel, now common throughout the U.S., to E15? Knowing that E15 has been shown to be less likely to 

volatilize its gasoline blendstock than E10, how does EPA anticipate this impacting ozone or other emissions? 

Has EPA conducted a sensitivity analysis to see what the implications on vehicle emissions and air quality 

impacts are for using E10 versus E15? What does EPA project concerning the penetration of E15 in gasoline 

blendstock? Is there a particular date by which EPA expects E15 to be commonly used like E10 is today? Please 

explain.

7) Will EPA also explain why aromatics and olefin percentages are adjusted? Is it in anticipation of higher 

oxygenate content and/or octane rating? Please explain. 

8) Will EPA explain under what circumstances vehicle manufacturers may request approval for an alternative 

certification fuel such as a high-octane 30 percent ethanol by volume (E30) blend for vehicles?