Light-duty vehicles emit gaseous and particle emissions that have the ability to effect climate, human health, and air quality. Vehicle technologies are changing rapidly due to the need to increase fuel efficiency. The use of biofuels (i.e., ethanol and iso-butanol) may increase due to the desire to reduce the use of fossil fuels. The changes in fuels and vehicle technologies may change the resulting emissions and need to be assessed. For instance, the water-soluble and water-insoluble particle composition could have detrimental health effects. This dissertation investigates the emissions of PM and gaseous emissions from current and emerging vehicle technologies.

The first section of the dissertation discusses a novel technique developed to determine the real-time Water-Insoluble Mass (WIM) fractions of vehicle emissions. The technique is then implemented in the following sections to infer the WIM fraction of vehicle emissions. The next section investigated the PM emissions from a number of hybrid, PFI, and GDI vehicle technologies on ranging aromatic concentrations and octane rating. The next section evaluated the gaseous and particulate emissions from PFI and GDI vehicles on varying concentrations of ethanol and iso-butanol fuels. Ethanol concentration ranged from E10 to E20 and iso-butanol fuels ranged from B16 to B32. The last section of this dissertation examined the gaseous and particle emissions from GDI and FFV technologies from vary concentrations of ethanol and iso-butanol fuels. For the GDI vehicles, ethanol concentration ranging from E10 to E20 and iso-butanol concentrations of B16 to B32 were used. The FFVs used ethanol concentrations were E10, E51, and E83 with an addition iso-butanol blend of B55. PM mass, Particle Size Distributions (PSDs), Particle Number (PN), BC/soot, Water-Soluble Organic Carbon (WSOC), and real-time WIM fractions were measured for the last three sections mentioned. Significant results on particle composition effects from vehicles, fuels, and driving conditions were found. Increasing vehicular speed increased particle hygroscopicity and decreased the WIM fraction. Alcohol concentration decreases the fraction of soot to the total PM mass for the GDI vehicles tested. Generally, increased ethanol concentration decreased the PN and PM mass.