The U.S. EPA’s Tier 3 emissions standards are being framed to align with the California’s Low Emission Vehicle (LEV)-III requirements.
“When we started planning the next phase of criteria pollutant regulations for light-duty vehicles, the obvious starting point was LEV-III because that would mean manufacturers could create a 50-state vehicle fleet,” Michael Olechiw, Director of the EPA’s Light-Duty Vehicle and Small Engines Center within the Office of Transportation and Air Quality, told SAE International Magazines.
Olechiw was a keynote speaker at a Center for Automotive Research (CAR) breakfast briefing on Dec. 5 at the Robert Bosch facility in Farmington Hills, MI. The event's topic was "Automotive Fuels and Emissions: Policies, Compliance, and the Potential Impact of Future Technologies."
A final rule on the Tier 3 standards is expected in late February 2014, according to Olechiw. “We’re trying to align two different programs that start in two different model years. The LEV III standards start in 2015, and the Tier 3 regulations start in 2017,” he said.
Under Tier 3, the light-duty vehicle fleet average for non-methane organic gases (NMOG) + NOx emissions would be 30 mg/mi in MY2025.
“We’re getting down to some very, very low levels,” said Olechiw. "Right now we’re under the Tier 2 program, and in the NMOG + NOx space the standard is 160 mg/mi. So the change of going from 160 mg/mi to 30 mg/mi for a final fleet average means a roughly 80% decrease in NMOG + NOx."
Tier 3 will adopt the LEV III curves at the program’s start. For vehicles less than 6000 lb GVW, the step-down for NMOG + NOx goes from 160 mg/mi in 2016 to 86 mg/mi in 2017.
For particulate matter (PM), the Tier 3 standard is 3 mg/mi beginning in 2017. “During the phase-in, manufacturers will be allowed 6 mg/mi for in-use testing,” Olechiw said.
In addition to specific NMOG + NOx, PM, and other emissions requirements, the Tier 3 program addresses fuels as a system solution.
“We have an agreement with the California Air Resources Board that they will accept Tier 3 fuel for certifications. This was an important point because manufacturers wanted the opportunity to run one test on one vehicle with one fuel and use that data for both certification in California and for federal certification,” Olechiw said.
Fuel composition also gets updated in the Tier 3 program.
“The Clean Air Act requires that certification fuel reflect actual in-use fuel. Right now, the certification fuel contains zero percent ethanol. The proposal is for E15, which is 15 percent ethanol,” said Olechiw, adding that the proposal also enables the use of regular and premium octane certification fuels.
In-use fuel used today has a 30 ppm sulfur average, but that will change.
“We’re looking at a 60% decrease in sulfur with the 10 ppm that’s proposed. We feel that the lower sulfur is required for vehicles to be able to meet these very stringent emissions. We’ve also proposed an 80 ppm cap,” said Olechiw, adding “we understand the manufacturers’ concerns for vehicles operating on 80 ppm sulfur because those vehicles will not be able to meet the standards.”
Stuart Johnson, Senior Manager of Powertrain Regulatory Affairs, Advanced Technology for the Volkswagen Group of America, said Tier 3, LEV III, and other emissions regulations are prompting powertrain revisions. VW’s product portfolio will spotlight two four-cylinder gasoline engines, the EA211 and the EA888, as well as a four-cylinder diesel engine, the EA288, Johnson noted during his comments at the CAR breakfast briefing.
“These three engines are central to our powertrain strategy," he said. "All three are direct-injected, turbocharged engines, and all will have variable valve timing. Our introduction of VVT on a production diesel engine is likely to be an industry first.”
VW’s new powertrain-related technologies will create an environmental ripple effect, including reduced engine-out emissions and lowered CO2 emissions thanks to optimized combustion and fuel-injection strategies, improved friction and warm-up performance, as well as engine weight reductions of up to 30%.
“Because of the modular design of these 4-cylinder engines, multiple global markets will be able to use these 4-cylinder engines while meeting local cost targets,” said Johnson.
EA211’s engine family architecture encompasses displacements from 1.0 to 1.6 L. The MY2014 Jetta Hybrid for the U.S. market features a 27-hp electric motor and a 1.4-L version of the EA211. “Although this engine isn’t equipped with cylinder deactivation or an integrated exhaust manifold, both technologies are coming on future versions of the EA211,” Johnson said in an interview with SAE Magazines.
The EA888, which covers displacements ranging from 1.6 to 2.0 L, debuted in MY2004. Now in its third generation, the EA888’s refinements include a new thin-wall cylinder block. Future models of the EA888 will feature a cylinder head with integrated exhaust manifold, Johnson said.
VW’s 4-cylinder EA288 diesel engine will use second-generation cylinder pressure control and a 2000-bar (29-ksi) high-pressure injection system on the base module. With displacements ranging from 1.6 to 2.0 L, it will use a complex exhaust gas recirculation system (with high-pressure EGR and cooled low-pressure EGR) as well as a water-cooled intercooler and EGR valve integrated with the intake manifold.
“The EA288 also has the intake and exhaust port on one camshaft. That enabled engineers to adjust the timing on both the intake and exhaust sides. This feature is comparable to having a Miller Cycle on a diesel engine,” Johnson explained.
Exhaust aftertreatment technologies on the EA 288 include a diesel particulate filter combined with a selective catalytic reduction catalyst packaged close to the engine. The diesel engine production debuts in the 2014 calendar year on the MY2015 Beetle, Golf, Jetta, and Passat.
The EA888, EA 211, and EA288 family of engines will comprise about 95% of VW Group’s global volume for hybrid-electric and non-electrified vehicles in the coming years, according to Johnson.
“VW Group is targeting production of 10 million vehicles worldwide in 2018. And about 20 percent of those vehicles will fall under the U.S. regulatory standards in North America and South America,” he noted.