The goal of this final year project was to find information about modifications that improve car fuel economy and factors affecting fuel consumption, and also to test these modifications and find out how they affect fuel consumption. The author also wanted to build a car of his own. The project was chosen because the author had previous experience of improving car fuel economy and driving economically. The project did not have an external client.

The thesis examines aerodynamic modifications, engine modifications, other mechanical modifications and the effect of driving behavior. The achieved improvements were examined by physical measurements, which measured either the decreasing of fuel consumption directly or the distance the car was coasting. Some data on the effect of different modifications and driving behavior on fuel consumption was obtained during this project. Fuel consumption of the project car decreased by 0.78 liters per one hundred kilometers. The effect of driving behavior was tested on another car. Fuel consumption after the change in driving behavior decreased by 3.5 liters per one hundred kilometers.