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

Abstract

Engine downsizing is a promising method to reduce emissions and fuel consumption of internal combustion engines. The main concept is to reduce engine displacement volume while keeping the needed output characteristics unchanged. The issue has become one of the most current fields of interest in recent years after the International Energy Agency set a target of a 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 highlighted. The global attention in these categories, the countries involved and the trend change in the last four years are presented in detail.