The daily star-mirror. (Moscow, Idaho) 1911-1939, 1923-08-25
GOVERNMEN7nHAS
GAS Saving Plan
WOUED ADJUST CARBURETORS
BY GAS TEST-BIG INCREASE
In MILEAGE SHOWN

Washington, D. C.-Substantial
savings of gasoline by the periodical
adjustment of carburetors based on
the results of analysis of exhaust
gases from automobile engines are
declared to be feasible by the de-
partment of the interior following
experiments made by the bureau of
mines on the fleet of motor trucks
used by the government fuel yard in
Washington. AS the result Of car
buretor adjustments made by gas
analysis in the bureaus experiments,
an actual increased efficiency in
mileage and saving of gasoline
amounting to % per cent was at
tanned In the following month The
tests demonstrate that a portable
carbon dioxide indicator for testing
the exhaust gases of a motor We
hicie gives a positive indication of
the carburetor adjustment, removes
all guess work of such adjustment,
is perfectly feasible practically, and
is almost indispensable to company
having ten or more large trucks in
service, especially if supplied with
adjustable carburetors.
The government fuel yard trucks
tested by the bureau of mines ranged
in capacity from 21s to 7k tons.
During the winter months, when the
demand for coal is heavy, from 80
to IS trucks are used. Samples of
the exhaust gas were taken on the
trucks kept in service for summer
hauling in order to determine the
carburetor adjustment as used.
Changes were then made to more
economical adjustment wherever
possible, without sacrificing flexi-
bility of operation and power. In
every case the adjustments were |
maintained for maximum power, but |
were adjusted to the leanest position |
to give that power. In all but one !
case the carburetors were found to be |
apparatus.
The bureau suggests that one driver
may be able to get considerably more
mileage than another due to the
method of driving. The mileage is
greatly increased by disengaging the
clutch whenever possible and coast
ing. In approaching heavy grade,
sufficient momentum should be OBJ
tanned to carry the vehicle consider
able distance up the grade before
The general condition of the truck
Is important in determining the mile
age which may be obtained, chief of
which are ignition, compression, in
ration Of tires, and condition of the
brakes. One missing cylinder may
make it necessary to run most of
,he time in second gear If the COM
preston is poor, owing to lealzy pis-
on rings, scored piston, or leaky
yalves, the mileage will be greatly
educed. The initiation of the tires
S important. One binding brake may
decrease the mileage to considerable
xtent
Weather has marked effect on the
Mileage obtainable. In general, a
actor runs Better at higher humidity
nd temperatures. Rainy weather de-
djusted too rich for maximum power
nd economy
The actual increase in mileage
nd saving of gasoline due to the
arburetor adjustments made by gas
nalysiS, when the month previous
nd following the adjustments are
)mpared, showed an increase in
iieage of % per cent; for the Sec
ad month after adjustment, 16 per
mt, and for the third month, per
mt. When the mileage is compared
uck for truck, and not taking into
'nsideration the distance each
aveied during the month, the in
eased mileage equaled 247, 212,
Id 1872 per cent, respectively.
The adjustment of carburetors by
alysis of exhaust gas is based upon
e fact that the carbon dioxide in
. exhaust is a direct indication of
9 air-fuel ratio and completeness
combustion. In turn, the air fuel
ito and completeness of combus-
n tells whether the carburetor is
)perly adjusted for maximum power
gasoline economy.
)her conditions being constant, the
eage Obtainable varies as the per-
ltage of carbon diOxide in the ex-
Ist gas and air fuel ratio. This
been little realized by most gar
men in the past The other fac
3 are carefully watched and
rded against, while carburetor adj
tment is usually left to the me-
mic or driver who adjusts accord
to his own notions. Usually the
is far too rich for maxi
n economy. There are, however,
eptions to this rule. A determine
Of the carbon dioxide content of
exhaust gas while the vehicle
'eing operated on the road gives
,sitlve indication of the carburet-
and removes all guess
<.
- results Of the bureau Of mines
Driments show that adjustable
Iuretofp tend to become more
y adjusted with lapse Of time,
l1lAt the adjustments should be
m 1t least every two months
uoAntain the most economical adj
nents. II the monthly mileage is