Scania AB has opened the new CD7 climatic wind tunnel test facility, located at the Scania Technical Center in Södertälje, Sweden. This facility is designed for product development testing of heavy trucks and buses in a range of controllable environments. Having this unique test environment at the main development center enables Scania to test its vehicles in a controlled repeatable environment year round, improving lead times from design to production, producing higher quality and more reliable vehicles, and significantly improves the capability for large vehicle performance research.This state-of-the-art facility provides environmental conditions from -35°C to 50°C with humidity control from 5 to 95 percent. The 13 m2 nozzle wind tunnel can produce wind speeds up to 100 km/h. The dynamometer is rated at 800 kW for the rear axle and 150 kW for the front axle, which also has ±10° yaw capability.In addition to the ‘standard features’ listed above for a climatic wind tunnel, this facility includes several additional capabilities. A Flow Control Device to improve the aerodynamic simulation around the sides of large, long vehicles in the test section was developed and implemented. Acoustic treatments in the circuit and test section plenum were designed to produce low background noise levels suitable for vehicle acoustic tests. This facility is also capable of producing complete simulation of solar, rain, snow, and soiling conditions. Moreover, emissions can be measured under road load conditions and in varying climates with different supplies of fuels.This paper describes the engineering design of the climatic wind tunnel, important aerodynamic and thermal commissioning results, and performance validation results from initial tests with vehicles.