Good and bad driving over short distances

TM 9-2320-211-20-3-2

(4) Good and bad driving over short distances. Reading the speed field

alone will not give true operation of the truck. Heavy trucks used for short hauls

in heavy traffic must also be covered. Even with law speed limits and heavy traffic,

the driver still has control of the economy of his truck. Two different drivers driv-

ing the same route can have the same chart readings and still have different driving

and economy readings. When the speed field is read with the engine rpm field, you

can then figure out the way the truck is being driven. The charts in Fig. 20-9 show

two trips on a scheduled route with good economy driving, and two trips with bad

economy driving. The Speed field recordings show very little difference between each

trip, but look at the rpm fields. In one case, the rpm recordings show good economy

driving. In the other case, the engine was run at the highest rpm in each gear.

There was only a very small difference in the time it took to finish the trips.

Good and Bad Driving Over Short Distances