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General Motors commented in generally positive tones about the Tier 3 rule, issuing a tentative commendation to the EPA for effectively harmonizing federal and state emissions requirements. Shown is the Buick Regal's standard engine, a four-cylinder turbocharged 2.0-L unit with direct injection delivering 259 hp (193 kW) and 295 lb·ft (400 N·m).

EPA finalizes Tier 3 program for lower vehicle emissions and low-sulfur gasoline

U.S. EPA Administrator Gina McCarthy today signed off the Tier 3 rule that mandates lower levels of pollutant emissions from light- and heavy-duty vehicles while also mandating significantly lower levels of sulfur in gasoline to help achieve the emissions reductions.

For light-duty vehicle, light-duty truck, and medium-duty passenger vehicles, the tailpipe emissions standards call for an 80% reduction in fleet average NMOG+NOx compared to current standards, and a 70% reduction in per-vehicle PM. The fully phased-in Tier 3 heavy-duty-vehicle tailpipe emissions standards for NMOG+NOX and PM are about 60% lower than current standards. The fully phased-in evaporative emissions standards represent a 50% reduction from current standards.

The sulfur content of gasoline is to be reduced (beginning in 2017) from the current 30 parts per million to 10 ppm on average, with the idea that catalytic converters will perform their emissions-reduction functions much more effectively at low sulfur levels. In 2030, when Tier 3 vehicles will make up the majority of the fleet as well as vehicle miles traveled, NOx and NMOG emissions from on-highway vehicles will be reduced by about 21% and CO emissions will be reduced by about 24%. National emissions of many air toxics from on-highway vehicles will also be reduced by 10 to nearly 30%.

Reductions will continue beyond 2030 as more of the fleet is composed of vehicles meeting the fully phased-in Tier 3 standards. For example, the Tier 3 program will reduce on-highway emissions of NOx and NMOG nearly 31% by 2050, when vehicles meeting the fully phased-in Tier 3 will comprise almost the entire fleet.

Sure to be disputed, EPA says the health benefits of Tier 3 as measured in dollars in the year 2030 (five years after full phase-in) will be between 4.5 and 13 times the cost of the program ($1.5 billion) in that year. The emissions standards will add about $72 to the cost of the average vehicle in 2025, and in that same year sulfur mandate will add about a penny per gallon of gasoline, according to EPA; however, the agency estimates vehicle lifetime savings in fuel economy will be more than $8000.

General Motors took part in an EPA media conference call today on the Tier 3 program and issued the following statement.

“GM looks forward to reviewing the specifics of the Tier 3 final rule, but it appears EPA has effectively harmonized the federal and state vehicle emissions requirements. We commend the agency for understanding the importance of this objective and creating one set of emissions standards for our vehicles nationwide.

In addition, we support the provisions for lower sulfur levels in fuels. Since the vehicle emission system and the fuel used act together in determining the emissions performance of the vehicle, automakers need cleaner fuels to achieve the lowest possible emissions. In addition, cleaner fuels provide the added benefit of reducing emissions immediately across the entire on-road fleet.

And finally, we commend EPA for selecting a certification fuel that is representative of in-use fuels. This allows OEMs to optimize vehicle performance to an actual fuel that our customers use nationwide.”

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