Currently, fuels and engines are developed and deployed in parallel, with little strategic interplay between original equipment manufacturers and fuel producers. The nine national laboratory Co-Optima program is working to change this paradigm and identify routes to co-optimization of fuels and engines with a focus on exploiting the unique properties of fuels derived from biomass. The program has investigated many biomass-derived blendstock candidates for use in co-optimized boosted spark ignition engines and is continuing a research agenda that involves mixing controlled combustion ignition engines. Applying techniques including life cycle analysis, Co-Optima’s analysis team, which Dr. Dunn leads, has estimated the potential benefits of deploying co-optimized fuels that incorporate bio-blendstocks. These analyses consider how supply of these bio-blendstocks will increase with time given the need for higher feedstock amounts, new biorefineries, and consumer decisions to purchase vehicles with co-optimized engines. These benefits analyses estimate energy and environmental benefits associated with various deployment scenarios including greenhouse gas savings, fossil energy savings, and changes in water consumption and air pollutant emissions. Finally, it is important to consider the potential use of the U.S. land base to produce feedstocks that might be used in the production of bio-blendstocks. Defensible techniques to estimate land use change and corresponding carbon stock changes remain an active area of research related to biofuel analysis.