Mesh setting in Solidworks Flow

Pls help me to select optimize mesh setting for calculating of drag co efficient. I am using mesh basic mesh level 8 and want to create more accurate meshing by changing minimum gap and mesh refinement level & other factors...pls tell me wht should b the best setting for aerodynamic analysis??? also please tell me how can i used adaptive mess techniques?? i am using solidworks 2011. Please reply as soon as possible...plsss..

thanking you...