Technical Paper
The Effect of Oxygenated Fuel, Altitude and Temperature on CO Emissions
1989-09-01
892063
Several areas of the country have mandated or are considering the use of oxygenated fuel blends for the control of wintertime carbon monoxide (CO) emissions. Some of these areas are at high altitude. The purpose of this work was to evaluate the effect of oxygenated fuels on CO emissions in modern, closed-loop vehicles and characterize the effects of altitude and temperature on CO emissions. Eight vehicles equipped with closed-loop emission control systems were tested with two oxygenated fuel blends and a base fuel (Indolene). All had Reid Yapor pressure adjusted to 10 psi. The oxygenated blends, at 3.5% (by mass) oxygen, were 10% ethanol in Indolene and 20% methyl tertiary-butyl ether (MTBE) in Indolene. Federal Test Procedure (FTP) exhaust emissions were measured with all eight vehicles at standard conditions of 74°F and 982 ft. altitude.
