Engine Downsizing; Global Approach to Reduce Emissions: A World-Wide Review: A World-Wide Review

Engine downsizing is a promising method to reduce emissions and fuel consumption of internal combustion engines. The main concept is reducing engine displacement volume keeping needed output characteristics unchanged. The issue became one of the most filed of interest in recent years after the International Energy Agency defined a target of 50 % reduction in global average emissions by the year 2030. In this review paper, different aspects of researchers’ efforts on engine downsizing are configured and due to overlaps, categorized into five main areas. Each category is discussed thoroughly and recent works are pointed. The global attention into these categories, countries involved and the trend changed in recent four years are presented in details.