These General Electric Locomotives such as the ES40DC, ES44AH, and ET44AH are all part of the GE Evolution Series and are nicknamed by Railfans as GEVOs. Lets start off with the ES40DC: GE ES40DC: The GE ES40DCs and ES44DCs began production in 2004 and ended production in 2008. The GE Evolution Series began with the ES40DC and ES44DC, due to the US implementing the EPA Tier 2 Standards, which the ES40DC meets. These ES40DC locomotives are capable of producing 4,000 horsepower, have a GE 16-cylinder, four-stroke, 7FDL-16, and have DC traction motors. CSX ended up ordering 302 units numbered between 5200-5501. The ES40DCs on CSX's roster come in 2 paint schemes... The Standard YN3, and the YN3b Boxcar Logo Paint Scheme. They also came equipped with either a Nathan K5HL or a Nathan K5LA. ES40DC in YN3: ES40DC in YN3b: First Gen Nathan K5HL Sample: Second Gen Nathan K5HL Sample: Third Gen Nathan K5HL Sample: Nathan K5LA: GE ES44AH: The GE ES44AH began production in 2004 and is still being produced today for railroads outside of the US. The early ES44AHs on the CSX roster numbered between 700-819 have low number boards like the ES44DCs, and are EPA Tier 2 compliant. These early ES44AHs are mostly in YN3 with a select few in the YN3b paint. The rest of the ES44AHs on the roster feature High number boards, and are numbered from 820-999 and 3000-3249. The ES44AHs below 950 are in YN3 while the ES44AHs above 950 are in YN3b. These ES44AHs have 1st Gen K5HLs, 2nd Gen K5HLs, and 3rd Gen K5HLs, along with some K5LAs. GE ES44AH with low numberboards (YN3): GE ES44AH with low numberboards (YN3b): GE ES44AH (YN3): GE ES44AH (YN3b): The horn links from above can be used as examples again. GE ET44AH: The GE ET44AH is the Tier 4 complain locomotive from the Evolution Series. The ET44AH has 4,400 hp, AC traction motors, and a GE 7FDL-16 and are numbered between 3250-3474. They are also mostly equipped with Nathan 3rd Gen K5HLs with a few supporting other horns such as K5LAs. GE ET44AH: If Dovetail games would make these locomotives in game in would add more variety along with trains spawning with ES44AHs and ET44AHs as mid or rear DPUs. CSXT 911, 1776, and 3194, along with all of the sticker and spirit units could be added as a separate pack too. I think adding these locomotives is a step in the right direction for DTG as far as Modern American Locomotives go.