Introduction

Introduction
At the end of the 20th century, cars face two fundamental challenges: on the one hand, to increase the safety of the occupants to reduce the number of victims of road traffic crashes, as well as in industrialized countries, they are one of the leading causes of mortality; on the other hand, increase its efficiency to reduce resource consumption and air pollution, which are one of the main causes. That's in the 1970s encouraged mechanical engineers to develop new technologies to reduce the consumption of conventional engines (for example, controlling the mixing air-combunstible microprocessor or reducing the weight of vehicles) and to accelerate work on alternative engines.<br> <br>For example electrical cars with hybrid engines, this type of vehicle is extremely clean and quiet, and is ideal for urban traffic. In addition, as most power plants use coal, the widespread use of electric vehicles would reduce demand for oil. The disadvantage of electric cars is its high current cost (which, among other reasons, is caused by the low number of units produced).