In August 2013, the Illinois DOT, in conjunction with Amtrak and other state DOTs, released a joint procurement RFP for 32 high-speed (125 mph), diesel-electric engines for use on intercity corridor and commuter routes. Siemens won the bid with the new Charger engine. Of the 32 base engines, 21 would be allocated for Illinois and Michigan service, 6 would be for Amtrak California service and the remaining 5 being used on the Cascades service in Washington. The contract includes options for up to 75 additional engines for use on intercity corridor and commuter routes, and up to 150 engines for use on long distance routes for a total of 257 engines. The long distance engines would differ mainly in the following ways: larger fuel tank (2,200 gallons vs. 1,800 gallons) and higher HEP capacity (1000 kW vs. 800 kW). Caltrans exercised an option to purchase an additional 14 of the Charger locomotives for use in California in addition to the initial 6 orders for use on the Pacific Surfliner.