Fuel saving by the optimized use of cab roof fairings for typical articulated vehicle operating cycles

Abstract The aerodynamic benefits of cab roof fairings and the associated reduction of drag and fuel consumption have been well documented. Although considerable effort has been applied by many manufacturers and researchers to devise roof fairings of near-optimal design for individual cab-trailer combinations, published studies have taken little or no account of the proportion of operations that may be undertaken by a tractor either with poor fairing/trailer matching or without a trailer at all. Observed load factors have proved to be substantially lower than those quoted by fleet operators. Cycle simulations have been performed to revise the estimate of the potential gains that are available from aerodynamic fairings for realistic operating cycles and load factors. It is shown that even for high load factors significant cost savings may be made in some circumstances by the adoption of simple but easily adjusted fairings in place of more highly optimized but fixed geometry designs.