Comparison of diesel and petrol car fuel consumption with a study of the factors affecting vehicle fuel economy

Over recent years, diesel engines have become an acceptable power unit for the private car, offering low fuel consumption, longer engine life and reduced maintenance costs; This thesis describes a programme of tests conducted at the Department of Transport Technology, Loughborough University of Technology, on behalf of the Transport Assessment Division, T.R.R.L., and compares the fuel consumption of three Vauxhall Cavalier cars, viz., a l600LD diesel car and the l300GL and l600GL petrol versions. Using a number of statistical techniques, the work further investigates the effect a group of factors had on the fuel economy of the diesel test vehicle. The fuel consumption of the diesel vehicle was compared to the l300cc. petrol car which had a similar performance, and the two petrol cars were compared to show the effect different engine capacity had on fuel consumption. Seven test drivers, categorised by age and sex, participated in the tests which were conducted on a test route in the county of Leicestershire, encompassing all types of driving environments.