The main objective of this study is to express the fuel consumption change with speed change on Egyptian roads. In addition, to develop a model that relates the fuel consumption to speed. To do that, field tests have been conducted on two types of cars; passenger car and pick up truck. A digital multi-meter device was used to measure the fuel consumption at each single speed value. The tests were conducted on a straight portion of the ring road around Cairo. The fuel consumption was measured three times for each speed value starting 10 km/hr till 120 km/hr with 10 km/hr increment. The results showed that the optimum speed (for minimum fuel consumption) is 60 km/hr for the passenger car and 80 km/hr for the pick up truck.