ABAQUS/CAE-Creating Fluid Elements

I am trying to model the air inside a 195/65 R16 radial car tire using ABAQUS(6.6.1). I am interested in knowing the air cavity volume and pressure change due to vertical loading. I think fluid elements are the way to go. 

I would appreciate pointers with regard to creating fluid elements (examples, input files etc..) as ABAQUS/CAE does not support this feature.