Reducing the weight of a vehicle, which helps to reduce fuel consumption and emissions by a large extent, has become a research focus in the automotive industry. Application of magnesium alloy lightweight materials is one of the most lightweight methods. This paper introduces the characteristics of magnesium alloys and reviews the application of magnesium alloys in automotive industry at present. Along with the increasing popularity of cars, the problems that emissions from cars leading to environment pollution is becoming more and more serious and vehicle emissions accounted for 65% of the total air pollution. So energy saving and emission reduction is put forward over the world. The data come form the aluminum association shows that when the weight of a car reduces 10%, its fuel efficiency can be increased by 15%, that is, the fuel consumption can be reduced by 6%similar to 8%. Therefore, reducing vehicle weight is the most efficient way to improve energy saving and environmental protection of car. Practices show that magnesium, aluminum and plastic are sometimes substituted for steel, which can effectively reduce the quality of a vehicle. Magnesium is the lightest metal structure material, whose density is about 1.74g/cm(3). In view of this, magnesium alloy is the first choice material for energy saving and environmental protection.
