The aim of the research is to determine the impact of stone mastic asphalt gradations on permanent deformation rate. Four compositions of SMA-11 with different grading compositions were made in a full scale asphalt plant and two equally graded mixtures using different additives were mixed in a laboratory. Different raw material fractions of granite were used to vary the number of voids and the structure of the mineral carcass. Road bitumen 70/100 was used as binder. Asphalt slabs were made using roller compactor and tested with the help of a wheel tracking method. The results show a clear correlation between the number of air voids, grading composition and additives used in the mixture with performance observed in the wheel tracking test.