Vehicle fuel consumption is one of the most important operational characteristics of road vehicles. The fuel consumption can be determined by different methods under laboratory conditions or by carrying out drive tests. One of the possibilities to quantify a way of vehicle driving is to analyse the selected parameters of the fuel mixture electronic control system. The objective of the paper is to predict fuel consumption via parameters of throttle position and engine speed. The measurement was carried out in the laboratory of the Department of Road and Urban Transport by using a MAHA roller dynamometer. The result is an estimation of accuracy of such fuel consumption determination and its possible utilisation for a system of assessing the vehicle driving style of drivers.