14 BULLETIN 1447, U. S. DEPARTMENT OF AGRICULTURE 
COST OF USING TRACTORS 
Since cost items expressed as money units are subject to consider- 
able change, especially during periods of wide price fluctuations, the 
items of expense incident to the operation of these tractors have 
been expressed, wherever possible, in terms of physical quantities. 
The figures representing the quantities and costs of fuel, lubricants, 
and days of repair work as well as other items of expense are aver- 
ages for the three-year period, 1920 to 1922, and are the expenses 
incurred by the actual number of tractor owners reporting an ex- 
pense for these items. 
Over the three-year period records were obtained from the owners 
of thirteen 10-horsepower, seven 20-horsepower, five 28-horsepower, 
nineteen 40-horsepower, and thirteen 50- -horsepower tractors, or for 
the period, a total of 57 different tractors were represented. Records 
were obtained on 30 of these tractors for 3 years, on 10 for 2 years, 
and on 17 for 1 year, making for the three-year period a total of 127 
reports on the cost of using - tractors, divided as follows: 25 reports 
on 10-horsepower, 17 on 20- horsepower, 10 on 28-horsepower, 45 on 
40-horsepower, and 30 on 50- horsepower tractors. 
In the following tables are shown the itemized cost of operating 
tractors of different sizes. The items which have been considered 
as operating cost are fuel, oils and grease, repairs, insurance, depre- 
ciation, and interest. The yearly cost, divided by the total number 
of 10-hour days the tractor was used during the year, is the average 
cost of operation per day. The number of hours the tractor was 
used on a given operation, multiphed by the cost per hour of opera- 
tion, is the total tractor cost of this operation. 
The average prices paid for fuel and cylinder oil for tractors and 
combines are shown in Table 10 
TABLE 10.—Average prices paid for fuel and cylinder oil for tractors and motor- 
driven combines, 1920-1922 
Price per gallon 
Item 
~ 1920 1921 1922 
Cents Cents Cents 
Gasoline tttrisy = [eyes ds Te ee) eee Pe Sa epee ines Ne oa 30. 2 24.6 23.3 
IKEe@TOSENG 22 et ect Se gi Rn ag 9 lease Mg a on Dae nee Seman ee 21.6 Doe, 22.7 
Distillate: "set oe Ch ASR eR De ee Bi Se Ed Oe ere ee ee 20.9 PALE! ZIe5 
Gylin der: Oil sae, 32h ee See es ee ee cen 91.6 89.3 87.7 
FUEL, OILS, AND GREASE 
Average quantities of fuel and cylinder oil used by tractors of 
different sizes, per year and per 10-hour day, are given in Table 11. 
The quantity of fuel used per day depends largely on the size of 
tractor, but with tractors of the same size the fuel consumption 
varied considerably. 
