There is more pressure than ever on heavy-truck engineers to find and create significant improvements in fuel economy and reduce tailpipe greenhouse gas (GHG) emissions. This is being driven primarily by two factors. First, customers are looking for ways to improve their business model by reducing fuel consumption. Diesel fuel prices in the past few years have been volatile, ranging from $2.931/gal (Sept. 6, 2010) up to $4.159 (Feb. 25, 2013) and back down to $2.561 (Aug. 24, 2015), according to U.S. Retail Diesel Price data from ycharts (http://ycharts.com/indicators/us_diesel_price), showing the need to be prepared for possible upswings in fuel costs of 50% or more. Additionally, regulations are driving fuel-economy improvements and GHG reduction to unprecedented levels.