GRASS LAKE, MI – The auto industry has three years – and lots of hard work ahead – to meet stringent new U.S. EPA Tier 3 tailpipe emissions standards for passenger cars. Similar thresholds take effect for light trucks a year later.
Complying with the requirements will be enormously challenging and will force automakers to sell a lot more small fuel-sippers if they want to continue producing large pickups and SUVs.
A closer look at the pending Tier 3 regulations, which coincide with new greenhouse gas regulations targeting a fleet fuel-economy average of 54.5 mpg (4.3 L/100 km) in 2025, reveals what appears to be an insurmountable hurdle facing much of the industry unless consumer preferences change drastically.
The world of EPA certification is complex and onerous, but Tier 3 represents the first comprehensive new federal legislation for light vehicles since Tier 2 was adopted in 2005.
The new system uses 2012 as a baseline and targets criteria pollutants: oxides of nitrogen (NOx) and non-methane organic gases (NMOG) such as partially oxidized hydrocarbons (alcohols, aldehydes and ketones), says Ben Patel, vice president-clean air and global R&D at exhaust specialist Tenneco, a company on the front lines of Tier 3 compliance.
Not included among these emissions are carbon monoxide and unreacted hydrocarbons, which are regulated separately. Carbon dioxide is a greenhouse gas that is not included under Tier 3.
Tier 2 had eight bins in total. The lower the bin, the lower the allowable emissions.
Tier 2 Bin 8 was reserved for the “dirtiest” vehicles and limited combined NOx and NMOG output to 325 mg/mile, Patel says. There aren’t many production vehicles currently in that classification.
The more telling statistic is the 2012 baseline fleet average for combined NOx and NMOG, which is 187 mg/mile for light trucks (up to Class 3) and 160 mg/mile for passenger cars.
That’s the equivalent of the outgoing Tier 2 Bin 5, in which most vehicles are certified today. Many light trucks are certified in Bins 6 or 7.
By the time Tier 3 takes effect in 2017, those emissions levels must fall 46% to 101 mg/mile for trucks and 86 mg/mile for cars.
By then, Bins 6, 7 and 8 will exist no longer. Instead, there will be seven bins with numbers that correspond with the level of allowable criteria pollutants.
The dirtiest will be Bin 160 (equivalent to the old Tier 2 Bin 5), which will limit a vehicle’s combined NOx and NMOG output to 160 mg/mile.
From 2017 until 2025, the regulations will become more stringent to the point that Bin 160 and Bin 125 should become distant memories.
Quest for Bin 30
By 2025, every automaker’s fleet average for new passenger cars and light trucks, regardless of size or horsepower, must achieve Bin 30. That constitutes combined NOx and NMOG emissions levels of 30 mg/mile.
The biggest-selling non-hybrid vehicles today that meet Bin 30 are certain Honda Civics and BMW 3-Series sedans, says Tim Jackson, Tenneco’s chief technology officer. “It’s almost a quantum leap in criteria pollutants,” he says.
At that point, Patel says an automaker intending to sell one vehicle in Bin 160 must sell 13 vehicles at Bin 20 to achieve the Bin 30 fleet average.
“Even light-duty pickup trucks must achieve Bin 30 on average due to their high sales volume,” he says.
“In reality, all high-volume vehicles under Tier 3 must certify at Bin 20 or Bin 30, and only lower-volume vehicles can certify at Bin 50 or 70, with very low-volume niche vehicles certifying at Bin 125. Otherwise, the fleet average of 30 will not be achieved.”
Reaching Bin 30 in 2025 from current emissions levels will require an average 84% reduction in criteria pollutants for light trucks and 81% for passenger cars, Patel says. The dirtiest vehicles currently on the road in Tier 2 Bin 8 will need to scrub 92% of their criteria pollutants.
Automakers failing to comply with the regulations may be forced to increase incentives on cleaner vehicles or may need to limit the production mix of higher-bin vehicles in order to bring their fleet average in line, Jackson says.
“Fines or penalties are highly unlikely,” he says. “Tenneco's position is that even fullsize pickups can reach Bin 30.” The supplier has a demonstrator ’14 Ford F-150 equipped with technology to improve emissions and fuel economy.
Aiding in the tailpipe initiative is a Tier 3 requirement for cleaner gasoline. A typical sulfur level in U.S. gasoline today is about 50 ppm. When Tier 3 is fully implemented, sulfur levels will be limited to 10 ppm.
Thankful for Single Standard
As challenging as this new regulatory environment may be, Tenneco and automakers are pleased federal Tier 3 standards align with those in California and other states (particularly in the Northeast) adopting California’s rules. Tier 3 Bin 30 aligns with California’s SULEV requirement for super ultra-low emissions.
As a result of Tier 3, automakers no longer will have to produce California-spec vehicles to meet the state’s SULEV and PZEV (partial-zero-emission) requirements.
“There’s been this duplication of engineering and R&D to not only design but also certify two different systems,” Jackson says. “For the first time, we will get harmonization, so we are building one variation instead of two. By the time we get to 2025, it will be completely common.”
Without two standards, Tenneco occasionally would produce one exhaust system equipped with a catalytic converter loaded with different levels of precious metals for different regions of the U.S.
“But in other cases, there were actually additional catalysts for the California system,” Jackson says. “So the systems were more complex. It was double the design work for us.”
Jackson is convinced Tier 3 requirements will result in cleaner air and a healthier environment.
“If you are driving one of these Bin 30 vehicles in L.A., New York, Chicago or Detroit, you’re cleaning the air while you drive,” he says. “The air coming out the tailpipe by some measures is cleaner than the air going into the air filter. Therefore, if you drive a battery-electric vehicle, you aren’t helping clean the air.”
Tenneco is offering a host of technologies to help automakers reduce criteria emissions, including lightweight fabricated exhaust manifolds, close-coupled converters, electronic exhaust-gas recirculation valves, diesel particulate filters, selective catalytic reduction and NOx adsorbers.
Plus, the supplier is expanding its technical center here to include certification cells for running emissions test cycles.
“Our customers are asking us to do testing that can be submitted directly to the EPA for engine certification. We couldn’t do that before,” Patel says. “That’s an investment that will be phased in over the next 18 months. It will be a big differentiator for Tenneco.”
