2013 Subaru Impreza Owner's Manual - Page 384

11-14 Maintenance and service Drive belts It is unnecessary to check the deflection of the drive belt periodically because your engine is equipped with an automatic belt tension adjuster. However, replacement of the belt should be done according to the maintenance schedule in the "Warranty and Maintenance Booklet". Consult your SUBARU dealer for replacement. If the drive belt is loose, cracked or worn, contact your SUBARU dealer. Manual transmission oil It is not necessary to check the transmission oil level. Check that there are no cracks, damage or leakage. However, the oil inspection should be performed according to the maintenance schedule in the "Warranty and Maintenance Booklet". Consult your SUBARU dealer for details. Continuously variable transmission fluid It is not necessary to check the transmission fluid level. Check that there are no cracks, damage or leakage. However, the fluid inspection should be performed according to the maintenance schedule in the "Warranty and Maintenance Booklet". Consult your SUBARU dealer for details. & Recommended grade and viscosity Each oil manufacturer has its own base oils and additives. Never use different brands together. For details, refer to "Manual transmission, front differential and rear differential gear oil" F12-6.