22 DEPARTMENT BULLETIN 1254, U. S. DEPT. OF AGRICULTURE. 
TIRES. 
In 1920 each truck owner was asked to state witli what kind, of tires 
his truck was equipped, what he paid for them, what mileage he ob- 
tained in their use, and the kind of tires he then preferred. The 
replies showed that 36 per cent of the men reporting on machines of 
different sizes used pneumatic tires, 33 per cent solids, and 31 per cent 
used pneumatics in front and solids in the rear. In the 1920 reports, 
50 per cent stated they preferred pneumatics, 41 per cent preferred 
solids, and but 9 per cent preferred the combination. The owners of 
the 1-ton trucks were about evenly divided in their choice as between 
pneumatics and solids, while about one-sixth of the men reporting on 
this size recommended pneumatics in front and solids in the rear. 
Pneumatics were preferred by a large part of the men owning trucks 
smaller than 1 ton, and solids were given the preference by a large 
percentage of the owners of machines over 1 ton in size. 
The replies received in 1920 also indicated that pneumatic tires 
on 318 tracks averaged 4,500 miles, while the reports from 206 men 
showed that the solid tires on their machines averaged about 8,200 
miles. 
A comparison of the prices of truck tires in June, 1922 (the month 
in which the 1922 investigation was begun) with the 1919 prices 
showed that in 1922 the first cost of pneumatic tires similar to those 
with which the trucks reported on were equipped was about 70 per 
cent of the 1919 prices, while the solid tires cost about 80 per cent 
as much as in 1919. On this basis the charges per mile traveled by 
the two kinds of tires on the trucks of different sizes, after making 
allowance for the tires with which they were equipped when pur- 
chased, and not including the cost of inner tubes for the pneumatic 
tires, would be as follows : 
Cents. 
i-ton trucks, pneumatic tires LI 
f-ton trucks, pneumatic tires ■. 2. 
1-ton trucks, pneumatic tires 1.1 
1-ton trucks, solid tires 1.0 
li and 1^-ton trucks, solid tires 1. 4 
2-ton trucks, solid tires 2. 
So many of the -J-ton and f-ton trucks were equipped with pneu- 
matic tires that no figures for solid tires on these sizes are given, and 
so few of the trucks over 1 ton in size had pneumatics that only the 
cost of solid tires for the larger sizes are shown. A large percentage 
of the 1-ton machines were equipped with smaller tires than were 1 
many of the |-ton trucks, which fact accounts for the average tire 
cost for the 1-ton trucks being lower than for the : ,--ton machines. 
AVERAGE TRUCK COST PER MILE RUN. 
The average cost per mile of operating trucks of different sizes, 
as shown in the preceding pages, is summarized below. The items 
included are depreciation, interest on investment, registration and 
license fees, repairs, gasoline and oil, and tire costs. The tire costs 
are for pneumatics on the 1-ton and smaller sizes, and solids on the 
larger sizes. (See fig. 11.) No information was obtained as to the 
cost of taxes, housing, insurance, labor of owners in caring for the 
trucks, grease, nor inner tubes for pneumatic tires. Full insurance 
