In 1990, Burlington Northern converted EMD SD40-2 No. 7890 to burn natural gas fuel as an experiment to lower fuel costs and get cleaner exhaust emissions. The rebuild included SD45-like flared radiators due to the need for increased cooling capacities to go with the hotter operating temperatures the unit endures while burning natural gas. It also received modified power assemblies, including new pistons, and a special paint job. In the morning sun on July 27, 1992, No. 7890 sits with its assigned fuel tender at the engine facility at Glendive, Montana.