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Alternative and renewable fuels show tremendous promise for addressing concerns of energy security, energy supply, and CO₂ emissions. However, the new fuels have the potential to produce non-regulated exhaust components that may be as detrimental or worse, than currently regulated emissions components. For the 2009 SAE Clean Snowmobile Challenge (CSC), a commercially available Fourier Transform Infrared (FTIR) spectrometer was used to sample raw exhaust from eight student teams' snowmobiles for comparative analysis with a conventional emissions bench. The levels of CO₂, CO, NO , O₂, and THC were compared for the five operating modes, which included both gasoline- and diesel-powered snowmobiles. The fuel was either an ethanol blend for spark-ignition engines or a biodiesel for compression-ignition engines. Final emissions result scores varied by less than 2% between the conventional emissions bench and the FTIR.

An experimental study and analysis was conducted to investigate cold start robustness of an ethanol flex-fuel spark ignition (SI) direct injection (DI) engine. Cold starting with ethanol fuel blends is a known challenge due to the fuel characteristics. The program was performed to investigate strategies to reduce the enrichment requirements for the first firing cycle during a cold start. In this study a single-cylinder SIDI research engine was used to investigate gasoline and E85 fuels which were tested with three piston configurations (CR11F, CR11B, CR15.5B - which includes changes in compression ratio and piston geometry), at three intake cam positions (95, 110, 125 °aTDC), and two fuel pressures (low: 0.4 MPa and high: 3.0 MPa) at 25°C±1°C engine and air temperature, for the first cycle of an engine start.

Particular matter (PM) has been greatly concerned over the recent decades due to the constantly increasing restriction on its effect on environmental aspect. Oxygenated fuel such as dimethyl ether (DME) has been known to have beneficial impact on diesel engine emissions in terms of zero soot formation. In current study, under several ambient conditions including surrounding gas temperature and oxygen percentages, soot and emission formation of DME spray is investigated to provide a comparison with other diesel surrogate (n-heptane) and JP-8 surrogate fuels. One important work is to develop a number of chemical kinetic mechanisms with soot chemistry including the growth of polycyclic aromatic hydrocarbon (PAH) and nitro oxides (NOx) formation. Using the developing detailed mechanisms, several numerical approaches were introduced to provide an integrated picture of emission formations.