* Specific trim level: Different trim packages might have slightly different aerodynamic features (e.g., roof racks, spoilers).
* Testing methodology: Different testing facilities and methods will produce slightly different results.
* Vehicle condition: Things like added accessories (roof boxes, etc.) will affect the Cd.
While Ford doesn't publicly release the precise Cd for individual models and years, you can expect the 2006 Ford Expedition's drag coefficient to be in the range of 0.38 to 0.42. This is a typical range for SUVs of that size and era. Keep in mind this is an estimate. To get a truly precise figure, you'd need to find wind tunnel testing data specifically for that vehicle and configuration.
