The Chrysler Corporation is currently in the aerodynamic design phase of a slotted-wall automotive wind tunnel. This wind tunnel, with a 12-ft high by 20-ft wide test-section, is designed for aerodynamic, thermodynamic, and acoustic testing, and has a slotted-wall test section to minimize wall-interference effects. 1/12-scale tests were conducted on test sections with lengths of 51, 65, and 72 in. to determine the acceptable length of a slotted-wall test section having both turntable and dynamometer test positions. The effect of test-section length on the magnitude of the model pressure errors and the reference-speed correction required at the model and dynamometer positions, as well as the influence of the re-entry flaps on the test-section pressure gradient and on vehicle wake-development at the dynamometer position, were investigated.A test-section length of 72 in. (72 ft full-scale) was selected, based on the test results. This test-section length produced adequate wake-development at both the turntable and dynamometer positions.