Abstract As part of its midterm evaluation of the 2022-2025 light-duty greenhouse gas (GHG) standards, the Environmental Protection Agency (EPA) has been acquiring fuel efficiency data from testing of recent engines and vehicles. The benchmarking data are used as inputs to EPA’s Advanced Light Duty Powertrain and Hybrid Analysis (ALPHA) vehicle simulation model created to estimate GHG emissions from light-duty vehicles. For complete powertrain modeling, ALPHA needs both detailed engine fuel consumption maps and transmission efficiency maps. EPA’s National Vehicle and Fuels Emissions Laboratory has previously relied on contractors to provide full characterization of transmission efficiency maps. To add to its benchmarking resources, EPA developed a streamlined more cost-effective in-house method of transmission testing, capable of gathering a dataset sufficient to broadly characterize transmissions within ALPHA. This technique targets the range of transmission operation observed during vehicle testing over the EPA city and highway drive cycles. This paper describes the method and test results of the benchmarking process used to gather transmission data. With this method, the transmission is tested as a complete system, as opposed to disassembling the transmission components and testing each separately. To develop this test method, a 6-cylinder EcoTec 4.3L engine with a 6L80 six speed automatic transmission from a 2014 Chevrolet Silverado was installed in an engine dyno test cell. The transmission dataset includes gear efficiencies, torque converter slippage and K factors, oil temperature and pressure, and OBD/epid CAN bus data.The transmission data collected using this benchmarking method were supplied as inputs to the EPA ALPHA model including transmission gear efficiency, torque converter K factors, and spin losses. The ALPHA results were then validated to vehicle chassis dynamometer test data. Introduction During the development of the light-duty GHG standards for the years 2017-2025 [1 ], EPA utilized a 2011 light-duty vehicle simulation study from the global engineering consulting firm, Ricardo, Inc. This study provided a round of full-scale vehicle simulations to predict the effectiveness of future advanced technologies. The LD GHG regulation required that a comprehensive advanced technology review, known as the midterm evaluation, be performed to assess any potential changes to the cost and the effectiveness of advanced technologies available to manufacturers for MYs 2022-2025. For the midterm evaluation, EPA is using its full vehicle simulation model, called the Advanced Light-duty Powertrain and Hybrid Analysis Tool (ALPHA) [2], to supplement and expand upon the previous study used during the Federal rulemaking. ALPHA will be used to confirm and, if necessary, update efficiency data from the previous study, to include the latest efficiencies of advanced downsized turbo and naturally aspirated engines. ALPHA will also be used to simulate and investigate effectiveness contributions from advanced technologies not considered during the original Federal rulemaking, such as continuously variable transmissions (CVTs) and Atkinson-cycle naturally aspirated engines.Testing and Benchmarking a 2014 GM Silverado 6L80 Six Speed Automatic Transmission2017-01-5020 Published 11/17/2017 Mark Stuhldreher EPA Office of Mobile Sources Youngki Kim University of Michigan John Kargul, Andrew Moskalik, and Daniel Barba US Environmental Protection Agency CITATION: Stuhldreher, M., Kim, Y ., Kargul, J., Moskalik, A. et al., "Testing and Benchmarking a 2014 GM Silverado 6L80 Six Speed Automatic Transmission," SAE Technical Paper 2017-01-5020, 2017, doi:10.4271/2017-01-5020.Downloaded from SAE International by University of Michigan, Sunday, July 29, 2018In the past, EPA has relied on contractors to provide full benchmark testing and characterization of transmissions to build comprehensive efficiency maps which w