If you are looking to drive American trucks in ETS2 1.40, you generally need a "Truck Conversion" mod.
: The Super Stripes DLC was updated to include matching trailer paint jobs, allowing for a fully unified truck and trailer look. Using American Trucks in ETS2 1.40 AMERICAN TRUCK PACK FOR ETS2 1.40
: High-dynamic-range skyboxes were added to provide more realistic weather transitions and sunset/sunrise effects. If you are looking to drive American trucks in ETS2 1
: Support for 4x2, 8x4, and 8x6 chassis configurations was introduced, allowing for heavy-haul setups on American rigs like the Western Star 49X. and 8x6 chassis configurations was introduced