A steel mill uses four functionally identical heavy vehicles manufactured by two different manufacturers. The information of failure time and downtime is available. This paper aims to compare the field reliability of the vehicles based on the field repair reports. A cost model is developed to comprehensively evaluate the overall performance of the vehicle. The preventive maintenance frequency of the vehicle is determined based on an empirical approach. The study is useful for the manufacturer to have a clear picture on the competability of its product and is also useful for the user to select an appropriate model of vehicles.