Because of complex nature of hybrid cars, control strategy designed by engineering sight usually cannot bring about the optimum performance of the car. The energy saving system of a hybrid car is evaluated by two main indices; special energy, special power and cycle of life span. Flywheels are a suitable source of energy for replacement of batteries due to ability of especial energy and especial power, but access to the technology for using it in cars needs more research and more achievement. The optimum system proposed include using battery and a super conductor concurrently which is based on fuzzy control on a refrence car in same level and using the fuzzy approach with help of fuzzy for controlling the performance point of combustion engines as the second level. Optimization of the performance point of a combustion engine is done with the aim of lower fuel consuption at the fisrt level and lower air pollution at the second level. And also super conductor is used to improve the instatnt acceleration of car, higher duration of car’s battery and supporting the lower consumption. Aims of this thesis is to increase the instant acceleration and increase the acceleration of 0 to 100 km and capacity to ride in high slopes and also establishing suitable environment to use electric motor in a way to reduce the fuel consuption and also the super conductor can improve both the energy absorption level and charge level so that it increase the battery life time. One of the main characteristis of ultra capacitors is high special power and this one for batteries is high special energy. So that, hybrid battery and ultra capacitor can improve electrical motor power to provide required power but also decrease the size of engine and increase the electrical motor for energy saving system back-up. In this research, Toyota Prius has been chosen as a reference. UDDS, FTP and INDIA SAMPEL drive cycle have been selected as evaluation indices. Fuzzy rules used in energy saving system is implemented according to some principal rules. First, we tried as much as possible, to keep the battery charging in the suitable area. Second, to provide the demanded power at the time requested, third when there are high powers requested or generated (brake power) super conductor will be used. And fourth, when the required power from the system is not that much and battery also has sufficient power donot use the super conductor and solely use the battery.The control of saving energy system with fuzzy logic has been designed to choose hybrid functional modes like when only the battery exchanges energy or when only the capacitor exchanges energy or whenever the battery and the capacitor co-operate to produce energy – in other words, both charge or take energy or when the battery provides demanded energy and charges the capacitor. capacitance selection is based on how effective it is on output. One of the important purposes of designing of saving energy system is to achieve higher instantaneous acceleration of a car, extend battery life time, grade ability test, and be supportive in order to decrease fuel consumption. The combustion engine operating points will be regulated by fuzzy approach in such a way that demanding torque and speed will be increased by making charge level of saving energy system as input variable and the feedback of its status. As a result fuel consumption will be decreased. To compare proposal design with the output indices of a car such as charge level fuel consumption, pollution, speed, and acceleration test and also grade ability test will be compared with reference car and improvements will be reported. The main disadvantage of ultra capacitors is there cost which makes them not to use in hybrid cars by more researches on the advantage of using ultra capacitors. The significant result of this would be reduction of hybrid cars cost to persuade costumers to use them. Key word: energy saving system, electrical hybrid cars, vehicle battery, ultra capacitors, control strategy, fuzzy control.