A report released this week highlights the most significant breakthroughs of the last year in the U.S. Department of Energy’s (DOE’s) Co-Optimization of Fuels & Engines (Co-Optima) initiative, with details on findings that could translate into significant greenhouse gas and tailpipe emissions reductions. The collaborative research undertaking has brought together top scientists, engineers, and analysts from across the nation to examine how simultaneous improvements to fuels and engines can maximize energy efficiency and the use of renewable fuels, while decreasing transportation sector emissions for the entire on-road fleet.