Unique Calibration
WARNING: This page is about a different car, the 2019 Ford Police Interceptor Utility and 2019 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
The Emission/Corporate Average Fuel Economy/CO2 Compliance Department is responsible for assigning these calibration numbers. Unique identifications are assigned to cover similar vehicles to differentiate between tires, drive configurations, final drive ratios and other calibration-significant factors. These 2 characters are chosen by the analyst to provide identifiable information unique to each calibration. For example, using the number 2 to denote a 2- valve engine versus using the number 4 to denote a 4-valve engine provides an easily identifiable difference.