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This paper presents an uncertainty analysis of aerodynamic force and moment coefficients for production vehicles in an automotive wind tunnel. The analysis uses a Monte Carlo numerical simulation technique. Emphasis is placed on defining the elemental random and systematic uncertainties from the tunnel’s instrumentation, understanding how they propagate through the data reduction equations and under what conditions specific elemental error sources are or are not important, and how the approach to data reduction influences the overall uncertainties in the coefficients. The results of the analysis are used to address the issue of averaging time in the context of maintaining a maximum allowable uncertainty level. Also, a maximum error requirement in the vehicle’s installation is suggested to allow the use of rapid but approximate vehicle alignment methods without incurring errors that exceed the data uncertainty. Observed reproducibility results are presented spanning a 16 month period.

The Sverdrup Driveability Test Facility (DTF) represents a new type of partnership in automotive testing between a supplier (Sverdrup Technology) and an original equipment manufacturer (Ford Motor Company). The facility was designed and built by Sverdrup to Ford's specifications. It is also operated and maintained by Sverdrup, with Ford as its “anchor” client under a long-term lease-back arrangement. Test time that goes unused by Ford is made available to other customers. Wind Tunnel 8 (WT8) is one of the test facilities within the DTF, which includes two other climatic wind tunnels and several supporting test cells. This tunnel combines aerodynamic, acoustic, climatic, and powertrain capabilities within one facility. The airline was optimized during the design stage for the competing requirements of excellent flow quality, very low background noise, and climatic capability.