Test-Mesh Dependency Tests in Fluent

John

I've been working on a 2D vehicle geometry. I have meshed the car many times trying to get good number of points in the BL. I have 3 meshes, one dense, the other 0.25x less dense, and the last 0.5x less dense. I approximate the courant number from the smallest element surface area given by fluent and I keep the courant number to 0.05 for the three meshes and calculate the timestep (hence combining the Mesh and Time-step tests into 1 test). Last time I ran the tests, I got an increasing Cl with increased meshed density and less than a 1% difference between the drag. I was told that the result for Cl is going the wrong way. Is this true? Why? and how can I solve this? I have been stuck on this issue for a few weeks.

Thanks