Sometime later this year the first of the GHG 2021 trucks will hit dealer lots. To meet the first round of GHG reduction targets, these trucks will be fitted mostly with existing fuel saving technology; aero devices, low-rolling resistance tires, etc. To meet the 2024 and 2027 targets, truck makers may need to get a bit more aggressive in their use advanced technologies. HDT's Jim Park and Mike Roeth of the North American Council for Freight Efficiency discuss how truck and engine makers will achieve those goals. As well, Robb Janak of Jacobs Engine Brakes and Joel Morrow, moderator of the 9+ MPG Facebook page share their thoughts on engine cylinder deactivation and advanced engine downspeeding.