N nnkmenonMember Hi Mr.Donald,For 5w30 grade,the viscosity range is 9.30cSt - 12.50 cSt as per SAE viscosity grade for engine oils(SAE J 300 2004).In your case the 15.30 cSt is clearly out of limit for a 5w30 grade oil. 4/6/054:16 AM