A locomotive diesel engine emissions control suite includes retarding fuel injection timing and heating the diesel fuel. Switch locomotives are now required to comply with USEPA emission standards under 40 CFR Part 1033 regulations. Retarding the fuel injection timing reduces peak temperatures during combustion which in turn reduces production of Nitrogen oxides (NOx) but also increases emissions of particulate matter (PM), Carbon Monoxide (CO), and Hydrocarbons (HC) in the exhaust. Unrelated efforts to reduce the smoke in diesel exhaust by pre-heating the diesel fuel showed an unexpected reduction in PM, CO, and HC. Such heating of the diesel fuel did not affect the reduction in NOx but reduced emissions of PM, CO, and HC to acceptable levels. Further experiments showed that two degrees of fuel injection retarding and fuel heated to 120 to 140 degrees Fahrenheit resulted in meeting the 40 CFR Part 1033 regulations.