JimmyTime89

An is200 is compatible with 15W 40 and 5W 30. The first 2 numbers are viscosity in cold weather i.e lower that number better flow rate in cold conditions. So basically the 10W40 will flow better when cold than the15. However both the 10 and 15W40 have better hot temp range than the 5W30. Depends on where you live you select your oil on its operating conditions. You might want to change to 5W30 for winter and 10W40 for summer.