Reducing greenhouse gas emissions from the light-duty transportation sector will require both low-net-carbon fuels and significant improvements in vehicle and engine efficiency. More highly efficient engines will employ higher compression ratio, and higher power density turbocharged engines that enable smaller swept displacement volume (downsizing) and operation at lower engine speeds (downspeeding). These technologies can be pursued more aggressively with fuels that have greater knock resistance than fuels on the market today. We describe a study to identify potential biofuels that enable these spark ignition (SI) engine efficiency strategies. A list of potential biomass-derived blendstocks (both single components and mixtures) that can be produced thermochemically, biochemically, or by hybrid processes was developed. An online database of properties and characteristics of these bioblendstocks was created and populated. Fuel properties were determined by measurement, model prediction, or literature review. Screening criteria were developed to determine if a bioblendstock was a) suitable as a liquid transportation fuels and b) met the requirements for advanced SI engines. Criteria included melting point (or cloud point) < -10°C and boiling point (or T90) < 165°C. Compounds that are insoluble or poorly soluble in hydrocarbon were eliminated from consideration, as were those known to cause corrosion (carboxylic acids or high acid number mixtures), or those with OSHA hazard classifications indicating that they are known or suspected carcinogens or reproductive toxins. Compounds predicted to be less anaerobically biodegradable than methyl-tert-butylether (MTBE) and having water solubility greater than 10,000 mg/L were also eliminated. A minimum Research octane number of 98 was also applied. These activities produced a list of approximately 40 representative and promising bioblendstocks. Additional property data, including Motor octane number, heat of vaporization, and lower heating value were acquired for these bioblendstocks. While alcohols such as ethanol are well known as potential fuel blend components, a significant finding of this work is the significant number of low-molecular weight esters and ketones that appear to have very promising fuel properties.