I'm working on Ahmed's Body flow analysis Does anyone can inform me on how to calculate the pressure drag, forexample at slanted rear end. from solve-monitor-force i found cd about 150, that is more than 100. how can i fond reasonable cd values? thanks for attention.

See that your reference velocity and area is set correctly. Most probably you did not change those and fluent is using the default values of 1m/s and 1m^2. You can change these under report/reference value. Anindya