The Monmouth inquirer., 1923-10-04
i, s. EXPERIMENTS
CUT COST OF GAS
Adjustment Of Carburetors on
Government Trucks Reduces
Consumption of Fuei.

NEUTRALITY-SUSPICIOUS. savings OF
gasoline by the periodical adjustment
of carburetors based on the results OF
analysis Of exhaust gases from auto
mobile engines are said to be feasible
by the Department Of the Interior
following experiments made by the
bureau Of mines ON the feet Of motor
trucks used by the government fuel
yard In Washington. AS the result OF
~carburetor adjustments made by gas
analysis In the bureaus experiments,
an actual increased efficiency in mile
age and saving Of gasoline amounting
to 22 per cent was attained. The tests
demonstrate that a portable carbon
dioxide Indicator for testing the ex-
haust gases of a motor vehicle gives q
positive Indication Of the carburetor
adjustment, remove all guesswork OF
such adjustment and is perfectly feas-
ibie practically.
Samples of Gas Tested.
The government fuel yard trucks
tested by the bureau of mines ranged
In capacity FROM two and g. half to
seven and a half tons. During the
winter months, when the demand for
coal is heavy, from 30 to 81 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 ADJUST
ment as used. Changes then were
made to a more economical ADJUST
ment whenever possible, without sac
rinclng iextbility of operation and
power. In ell but oAe case the car
buretors were found to be adjusted too
rich for maximum power n economy.
increase in Mileage Noted.
The actual increase in mileage and
saving Of gasoline due to the carbure-
tor adjustments made by gas analysis
when the month previous and the
month following the adjustments are
compared, showed an increase In mhe-
age Of p per cent for the second
month after adjustment, 10 per cent,
and for the third month. 8 per cent.
When the mileage is compared truck
for truck, and not taking into constd-
Grafton the distance each travelled dur
ing the month, the increased mileage
eQualed PAT, 21.2 and 1862 per cent,
respectively.
The adjustment Of carburetors by
analysis Of exhaust gas is based upon
the fact that the carbon dioxode in
the exhaust is a direct indication of
the air-fuels ratio and completeness Of
combustion. In turn, the air-fuel
ratio and completeness of combus-
ttpn tell whether the carburetor is
properly adjusted for maximum power
and gasoline economy.
Adjustment Usually Rich.
Other conditions being constant, the
mileage obtainabie varies as the per
centage Of carbon dioxide in the x
haust gas and air-fuei ratio. This has
been little realized by most garage
men In the past. Usually the adjust
ment Ia far too rich for maximum
economy. There are. however, excep-
lions to this rule. A determination of
the carbon dioxtde content of the Il
haust gas while the vehicle is being
operated on the road gives a positive
Of the carburetor adjust
ment.
The results of the bureau Of mines
show that adjustable ar
buretors tend to become more richly
adjusted with lapse of time, and that
the adjustments should be checked at
least every two months to maintain the
most economical adjustments.
Driving Is a Big Factor.
The bureau suggests that Il driver
may be able to get considerable nor
mifeage than another. due to. tho
method Of driving. The mileage is
greatly increased by disengaging the
clutch whenever possible and coast
ing. In approaching a heavy grade
sufficient momentum should be OBJ
tanned to carry fife vehicle a consider
able distance UP the grade before maxi
ing it necessary to change the gears.
Weather has a marked effect on the
mileage .obtainable, In general, a mo-
tor runs better at higher humidity and
temperatures. Rainy weather de-
creases the mileage on account Of the
slippery nature Of the streets; so does
snowy weather.