Relationship between Gross Weights and Horsepowers of Commercial Vehicles Operating on Public Highways

This study investigates the relationship between the gross weight and net engine horsepower of commercial vehicles. The data were used to update current information on weight-power ratios of trucks and investigate the trend in the ratios since 1949.

There is a definite increase in the weight-power ratio as the number of axles increases, regardless of vehicle type. There is also an overall trend to lower weight-power ratios as evidenced by a 12% reduction in the ratio from 1949 to 1955 and a further reduction of 28% from 1955 to 1963. A performance requirement of 400 lb/hp is liberal and would affect only a small percentage of the total trucks.