Pa. Mulawa et al., EFFECT OF AMBIENT-TEMPERATURE AND E-10 FUEL ON PRIMARY EXHAUST PARTICULATE MATTER EMISSIONS FROM LIGHT DUTY VEHICLES, Environmental science & technology, 31(5), 1997, pp. 1302-1307
During the winter of 1994-1995, the State of Alaska Department of Envi
ronmental Conservation conducted a multifaceted program designed to ev
aluate the impact of switching from regular gasoline to an E-10 fuel (
gasoline with 10% ethanol) in Fairbanks. As part of that program, 10 i
n-use vehicles were tested on a chassis dynamometer at temperatures of
20, 0, and -20 degrees F using both fuels. Three of these vehicles we
re retested in the EPA facilities at Research Triangle Park, NC, under
the same conditions. Vehicles were driven over the Urban Dynamometer
Driving Schedule of the Federal Test Procedure during testing. PM-10 e
xhaust emission samples were collected at Fairbanks, and total particu
late samples were obtained at the EPA. Results from both parts of this
study indicate that particulate matter (PM) emission rates increased
with decreasing temperature for both fuels. The increase occurred prim
arily during cold starting and is assumed to be due to enrichment. Par
ticulate matter emission rates during operation on the E-10 fuel were
lower relative to rates obtained during operation on the base gasoline
. Exhaust hydrocarbon and PM emissions were well correlated, suggestin
g that fully phased-in Federal Tier 1 vehicle emission standards will
reduce PM emissions from new vehicles and that rich-operating, high em
itters can be expected to have high PM emissions.