THE results of a study to determine practical values for the performance factors of trucks are presented here.
Relationships for determining rolling resistance, air resistance, grade resistance, chassis frictional resistance, power loss due to altitude, and the mass equivalent constant are given that closely approximate actual performance figures.
It is pointed out, however, that there exists considerable controversy in the industry over some of these factors, especially those for air resistance and chassis frictional resistance, indicating that an experimental research program is definitely required to develop sound engineering values for these two resistances.