Research On Automobile Fuel Economy Evaluation Method

Guaranteeing power performance,the ability that automobile travels economically with possibly less fuel consumption is called automobile fuel economy. The vehicle fuel consumption of per hundred kilometers under specific conditions or the running kilometers of the car with given fuel is commonly used to weigh automobile fuel economy. Recent years, with the problems of fuel price, resources, environment standing out, automobile fuel economy has becoming a hot topic among car manufacturer and consumers. Therefore, various countries started to formulate the fuel evaluation standard to promote the automobile fuel economy. Experience showed that the rationality of fuel economy standard is one of most effective tools to control the demand of petroleum and the emission of greenhouse gas. Especially to a country like ours, depending on the rapid development of annual output and inventory and limited petrol resources, it is significant to generate a thorough standard to evaluate automobile fuel economy.There have been a large amount of researches on the automobile fuel economy home and abroad, such as the European ECE, the American FTP75 and the Japanese 10-15. Various countries’standard systems as well as corresponding experimental conditions evaluating the automobile fuel economy, have been elaborated. Through analyzing the national methods of evaluating fuel economy, some main existing problems in the experimental methods have been proposed, laying the foundation to formulate a more reasonable economy evaluation standard in automobile fuel.The paper also discusses various conditions influencing vehicle fuel consumption in the actual running course. And a new evaluation method, that is using the weighted average method to calculate fuel consumption of motor vehicles is proposed. Using weighted average method to evaluate automobile fuel economy can describe fuel economy accurately, taking factors like road condition and load condition into consideration. By the comparison with previous national fuel economy standard and similar vehicle types, the new fuel economy standard is basically same as that of real vehicles, which proves the rationality.A good evaluation criterion needs to establish proper test cycle conditions. And only by establishing real operating conditions, can fuel economy be promoted. Some statistic analyses on typical vehicle driving conditions in Chengdu have been conducted to illustrate the synthetic method of the working conditions of various cars, and combined cars’ specific characteristics in domestic cities, to impove the current working conditions. On the basis of driving conditions of cars in Chengdu, fuel consumption per hundred kilometers of two types of cars is calculated respectively. Comparing with the actual value of fuel consumption, the formulated condition can be proved rational. And on this basis, after plentiful statistical analysis of typical conditions of domestic cities, reasonable national standards can be proposed referencing the evaluation method suggested in this paper.