Fuel Injection Nozzles Demonstrate Minimal Deposit-Forming Effects from Fuel Content: A fuel injection nozzle in a DI gasoline engine is exposed to gas at high temperatures in the combustion chamber and forms deposits on the nozzle tip. The deposits can alter the fuel injection characteristics and negatively affect engine performance and exhaust emissions characteristics. The T90 and aromatics in gasoline have been known to contribute to deposit formation. These properties in commercially available gasoline in the market vary within certain ranges. In addition, because of Japan’s initiative to reduce global warming gas, ETBE, which is made of bio-ethanol and iso-butane, has been blended in gasoline. Consumption of ETBE is expected to be about 840,000 kL in 2010 (equivalent to 210,000 kL of crude oil). Engineers at Nippon Oil and Toyota questioned how these fuel properties would affect deposit formation on fuel injection nozzles of DI gasoline engines. Seven different fuels were prepared as baseline fuels with different levels of aromatics, T90, and olefins. Another seven fuels were prepared with the addition of 7-volume-percent ETBE. The total of 14 fuels were tested on a 2007 model year, 2.944-liter, V6 DI gasoline engine that operated on stoichiometric mixture. After an eight-hour engine test under hill-climb conditions, the fuel injection nozzles were tested to measure any reduction in fuel flow rate due to deposits.