Bringing the street into the lab


MAHLE climatic wind tunnel

As the leading international OEM of vehicle air conditioning and engine cooling systems, we not only invest in research and development of our own products, but also provide our customers with comprehensive development services.

Our climatic wind tunnels in Stuttgart/Germany and Troy, Michigan/USA as well as our cooling wind tunnel in Stuttgart provide realistic conditions for measurement and testing without elaborate road testing. They provide a reliable basis for a smooth technology transfer, quality management, cost reduction, and time savings—all in the interest of our customers.

Since 1936, we have been employing wind tunnels in the development of thermal management solutions for passenger cars, commercial vehicles, and off-highway applications. In the year 2000, an entirely new climatic wind tunnel was added in Stuttgart-Feuerbach, setting new standards. This was followed in 2004 by the even more powerful Troy wind tunnel in the Troy Tech Center in Michigan.

Each MAHLE climatic wind tunnel is designed to allow unproblematic testing for a wide range of applications and a large number of measurements to be performed reproducibly.


  • Automobile manufacturers/suppliers
  • Commercial vehicle manufacturers/suppliers
  • Agricultural machinery
  • Outdoor work machinery and equipment (chain saws, ticket machines, etc.)
  • Insurances
  • TÜV/Dekra
  • Defense industry


  • Climate control systems, heaters
  • Weather stations
  • Wind/solar energy, power generation
  • Sports equipment and accessories
  • Cooling/heating insulation
  • Chemical industry (paints, varnishes, etc.)


  • Comparison of air conditioners
  • Testing and evaluation of components in cooling and heating circulation
  • Design and testing of engine cooling components
  • Tuning of climate control systems
  • Testing of channel and nozzle concepts
  • Evaluation of thermal comfort within the vehicle (e.g., using the MARCO thermal dummy)
  • Acceptance measurements by local approval authorities



  • Cooling curves to meet any specification
  • Heating measurements to meet any specification
  • Filling optimization in the cooling circuit
  • Stability and acoustic testing in the cooling circuit
  • Fuel consumption measurements in driving cycles such as MVEG and SC03, using a driving robot
  • Defrost and demist measurements, such as to ECE or FMVSS standards (acceptance measurements)
  • Climate control tests
  • Evaluation of interior acoustics

Vehicle preparation

3 x equipment box, passenger cars1 x equipment box, trucks
Platform liftx
Vehicle pitx
Tool cartxx
Exhaust gas extractionxx
Air conditioning service unitxx
ID card required for accessxx

There is also a mobile device for measuring air volumes, and the vehicles can be filled with fuel in stationary or mobile mode.

Vehicle equipment

  • Equipped with stationary measurement technology (NEFF)
  • Equipped with mobile measurement technology (CSM modules)
  • Vehicle equipped with measurement points for temperature, pressure, volume flow, humidity, and engine speed
  • Leak testing of the AC circuit using nitrogen
  • Air volume measurement

The MAHLE climatic wind tunnels stand out due to their versatility as well as their broadly adjustable system parameters such as chamber size, wind speed, temperature, humidity, solarium intensity, roller brake performance, and acoustics.


  • Open measurement section for passenger cars, vans, delivery vans, and commercial vehicles
  • All drive types (two rollers for front, rear, and all-wheel drive)
  • Chassis dynamometer with adjustable axes
  • Adjustable nozzle for different vehicle types
  • Solarium with solar altitude simulation and full sunlight spectrum
  • Precooling chamber for passenger cars and vans
  • Tunnel design for acoustic measurements in the vehicle cabin


Driving programs

  • Simulation of test drives
  • Precise reproducibility using a driving robot for passenger car, van, and delivery van measurements
  • ECE (fuel consumption, thermal management)
  • NEDC and Artemis

Environmental conditions

Recreating daily drives (solar altitude, atmosphere)

SpecificationsCWT StuttgartTWT Troy
Max. vehicle dimensions10.0 x 2.65 x 5.0 m (L x W x H)11,0 x 3,0 x 4.3 m (L x W x H)
Max. wind speedPassenger cars: 130 km/h for 6 sqm nozzle surface area
Van/delivery van: 110 km/h for 8 sqm nozzle surface area
Trucks: 90 km/h for 10 sqm nozzle surface area

Passenger cars: 200 km/h for 6 sqm nozzle surface area
Van/delivery van: 160 km/h for 8 sqm nozzle surface area
Truck: 120 km/h for 10 sqm nozzle surface area

Temperature range–30 to +50°C
(cool-down time <180 min from +50 to –30°C)
–30 to +50°C
(cool-down time <180 min from +50 to –30°C)
Humidity range5 to 95% rel. humidity5 to 95% rel. humidity
Solarium680 to 1,200 W/sqm intensity350 to 1,200 W/sqm intensity
Max. braking power, chassis dynamometer150 kW/axle from 30 km/h300 kW/axle from 35 km/h
Max. drive power>100 kW>250 kW from 35 km/h
Max. speed deviation0.5%0.5%
Background noise<70 dB(A) at 50 km/h<65 dB(A) at 50 km/h

Preconditioning chamber

CWT Stuttgart
TWT Troy
Max. vehicle dimensions4.9 x 3.3 x 2.2 m (L x W x H)8.0 x 4.5 x 3.5 m (L x W x H)
Temperature range–40 to +50°C–40 to +50°C
HumidityNot controllableNot controllable

We are a member of CAWA (Climatic Automotive Windtunnel Association), the coalition of European wind tunnel operators.