The study of the efficiency of fuel consumption by adjusting the fuel injection pressure is basically one optimization method to maximize the engine combustion. In this current study the Honda wave 110 cc. engine has been used to test in particular the fuel injection by adjusting the pressure of injector. To control the pressure of injection was made by automatic valve injectors with three different pneumatic pressure which were 2 2.5 and 3 bars respectively and the similar running distance of 5km. The results showed that at 2 bars the obtained fuel saving was 1020.68 km/L and the speed at 25.23 km/h which corresponded to the highest CO2 emissions during the engine combustion.

Nowadays energy conservation is widely recognized due to fuel crisis. Petroleum is one of the primary energy used in various aspects especially by factories which consume energy at very high rate. Air pollution has been caused for this reason. Lots of industrial sectors have paid attention to this problem and have found out in different ways to manage it. The purpose of this work was to apply compressed air energy which is zero emission energy as an alternative energy instead of fossil energy. This energy was used in a prototype small three-wheeler powered by an impact wrench. The vehicle carried two tanks of 10 liters of air which pressure is 90 bars. The three-wheeler used chains and gears to transmit power to wheels. The gear increased torque ratio of the impact wrench. An air valve was controlled by a sling-controlling lever. On rear wheel hub 3-speed gear was fitted to enable the car move conveniently according to speed of motor and road condition. Test results showed that air car could move with the maximum speed of 21.4 km/hr and the farthest distance of 1917 meters. The longest period of time which the car could move was about 5-6 minutes. The highest torque produced by impact wrench was 2.323 Nm at rotating speed of 3400 rpm. It was also found that between the rotating speed of 2000 and 4000 rpm the impact wrench produced the best performance and this is a good condition to be chosen for further research and development for maximum efficiency.

Nowadays the fuel energy is consumed more than it was used in the past and most of energy used comes from petroleum which is not reusable. Moreover the crude oil which is raw material to be refined is likely to take place in nature; it usually takes a long time. Therefore this natural resource must be used efficiently to maximize its benefits. Construction of Econo Power Car will be one of many methods to decrease the energy consumption. The objective of research aims to influence parameter effecting to the fuel consumption such as engine system transmission system suspension system and fuel injection system. Furthermore the Econo Power Car is estimated to cooperate with 11th Honda Econo Power. To achieve this the effects of fuel consumption parameters are investigated using experiments. For the suspension system the wheel resistance and the rolling resistance are decreased by wheel angle modification and changing the wheel bearing. Moreover the engine is adjusted by the fuel injector addition. For the economical experiment in the 11th Honda Econo Power the By Part Team (RMUTP Team) has the consumption 843.443 kilometer/liter and within 4th order from 347 teams by the invent higher education of competition and type of 125cc. The winner team has the economize statistics 999.746 kilometer/liter. As a result influence parameters of fuel consumption are wheel resistance and engine system which is good knowledge for the development of the Econo Power Car in the future.