ECONOMY ACCORDING TO THE BOOK OF VOLVO

The author summarises the latest attempts at Volvo to reduce the fuel consumption of their trucks. The turbocharged diesel engine is regarded to be the predominant form of power unit for some time. The efficiency of the engine can be increased by intercooling in the air intake, reducing the air temperature from 150 deg C to 50 deg C. Improved engine performance is to be further utilised by the introduction of a new 13-speed compound gearbox. Over a year's trial, trucks fitted with Allison automatic gearboxes were found to be little different in fuel consumption from those with manual gearboxes. Improvements in engine design and the use of possible alternative fuels are examined. Large increases in fuel consumption with speed suggested that driver attitudes are important. The importance of improved aerodynamic shape and its effect on performance and economy is examined. It is claimed that a 20 per cent reduction in drag could reduce fuel consumption by at least five per cent. The effects of air deflectors of various shapes are discussed. (TRRL)