RailWorks SD40-2 Burlington Northern Add-on is available on Steam.

The SD40-2 Burlington Northern shares the same basic superstructure as the SD38-2 as it uses the same 16-645E3 engine (with turbo charging modifications). The Dash 2 also has longer front and rear porches than other models, making for distinguishing features when comparing locomotives. Another alteration from previous designs is the three radiator grilles mounted on the roof, where previously there were only two.
Source RailWorks SD40-2 Burlington Northern Add-on is available on Steam.

The SD40-2 Burlington Northern shares the same basic superstructure as the SD38-2 as it uses the same 16-645E3 engine (with turbo charging modifications). The Dash 2 also has longer front and rear porches than other models, making for distinguishing features when comparing locomotives. Another alteration from previous designs is the three radiator grilles mounted on the roof, where previously there were only two.
Source