Metal-based fuel additives have been promising alternative choice to improve diesel engine performance and emission characteristics. Many studies have been performed on use of metal-based fuel additives such as magnesium, platinum, titanium, and cerium in diesel engine. Unlike conventional metal-based additives, Acetylferrocene and Ruthenium polypyridyl complex may be alternative metal-based additives for diesel. This study intends to investigate performance and emission variations of a diesel engine powered by diesel blended with Acetylferrocene and Ruthenium polypyridyl complex additives. In accordance with this purpose, a single cylinder, direct injection diesel engine was used to test these alternative metal additives. Results showed that Acetylferrocene and Ruthenium polypyridyl compl...