variants of the 5000 and 7000 severe-service trucks (today, the HX and HV-Series on-road). Joint ventures Current General Motors Navistar entered into an agreement to purchase General Motors' medium duty truck unit in 2007, but because of changing market conditions the purchase ultimately did not occur, and production of the Chevrolet Kodiak and GMC TopKick were discontinued in 2009 as GM entered bankruptcy protection. In 2015, a joint venture between the two companies for development of a new Class 4/5 commercial vehicle was announced. In early 2017, Navistar's truck assembly plant in Springfield, Ohio, began production of cutaway van chassis variants of the GMT610 Chevrolet Express and GMC Savana. Further details around the Chevy Silverado 4500HD/5500HD/6500HD were announced by General Motors early in 2018, with Navistar also unveiling the International-branded variant of the truck, the CV series, shortly thereafter. Production started in late 2018. The truck serves as a successor to the previously discontinued Chevrolet Kodiak and International TerraStar, competing against the Ford Super Duty F-450/F-550/F-600 and Ram Chassis Cab. Tatra Tatra and Navistar Defence introduced at Eurosatory Exposition in Paris, France (June 14–18, 2010) the results of their strategic alliance since October 2009, the models ATX6 (universal container carrier) and ATX8 (troop carrier) The vehicles appear to be based on Tatra T815-7 (T817) 6x6, 8x8 chassis, suspension and cabins while using Navistar engines and other components. Under the deal Navistar Defence and Tatra A.S. will market the vehicles in North America, which includes sales to the United States military and foreign military sales financed by the United States government. Tatra will source parts and components through Navistar's global parts and support network for Tatra trucks delivered in markets outside of North America, as well as market Navistar-Tatra vehicles around the world in their primary markets. Former Ford Motor Company From the 1980s to the 2010s, Navistar had a close relationship with Ford Motor Company. Commencing for the 1983 model year as an engine-supply agreement, the relationship evolved into a $400 million yearly business, culminating into joint production of entire vehicle lines. Following the end of the diesel-engine supply agreement after the 2010 model year, Ford and Navistar ended collaborative production of medium-duty commercial trucks after the 2014 model year Ford diesel V8 engine As a result of the gas crises of the 1970s, the implementation of Corporate Average Fuel Economy (CAFE), was applied to light trucks alongside automobiles. In