The EMD SD70ACe is the successor to the SD70MAC, with changes made to comply with stricter emissions standards. These units, equipped with a EMD 16-710-G3C-T2 prime mover, are rated at 4300HP (3200KW); with later 'Tier 3' models rated at 4500HP (3400KW). This unit, EMDX 2012, is a Tier 3 demonstrator unit sent by EMD to railroads for them to trial the latest Tier 3 SD70ACe technologies at the time on their roads; such as during mid to late 2011 with Norfolk Southern.