The Amoco “all-weather” chassis dynamometer is a closed-circuit, single-return, semi-open jet wind tunnel used primarily for automotive fuel and lubricant studies. Underhood temperature and loading conditions of cars operated on the road are accurately duplicated in the tunnel. Maximum vehicle and air speed is 145 kph (90 mph); maximum loading is 235 kW (315 hp). Two soak rooms adjacent to the tunnel are used to temperature condition cars for testing in the tunnel, for static car tests, or for enginedynamometer studies. Temperature and humidity in the tunnel and soak rooms are controlled independently from -40C to 49C (-40F to 120F) and from essentially dry to essentially saturated air.