Renewable diesel has become an increasingly common diesel fuel substitute in California. It is important to understand the effects renewable diesel use has on vehicle emissions. To determine how renewable diesel affects locomotive emissions, locomotive exhaust emissions testing was completed on various fuels and fuel mixtures at the Southwest Research Institute’s (SwRI) Locomotive Technology Center (LTC).
This report documents the effects of renewable diesel on locomotive exhaust emissions. A total of nine emissions tests were conducted on a 4500 horsepower (HP) US EPA Tier 3 GE ES44C4 locomotive using the following fuels and fuel blends: 100% CARB Diesel, 100% Renewable Diesel, 50% CARB Diesel/50% Renewable Diesel, 50% CARB Diesel/30% Renewable Diesel/20% Biodiesel, and 100% US EPA Certification Diesel. The exhaust emission and fuel consumption results from this testing provide a better understanding of the effects that various fuels and fuel mixtures have on locomotive emissions and fuel consumption.