2006 Subaru Impreza Owner's Manual - Page 301

11-22 Maintenance and service Each oil manufacturer has its own base oils and additives. Never use different brands together. Oil grade: API classification GL-5 -30 -20 -10 -20 0 20 0 40 10 60 20 30 80 90 85W 80W 75W/90 40 100 Recommended grade and viscosity Rear differential gear oil Your vehicle may be equipped with a rear differential protector. The differential protector provides protection to the rear differential assembly during off-road use. Removal of the rear differential protector is not required when checking the oil level. 1 Checking the gear oil level 3 1 SAE viscosity No. and applicable temperature B00032 2 1) Filler plug 2) Drain plug B00373 Remove the plug from the filler hole and check the oil level. The oil level should be kept even with the bottom of the filler hole. If the oil level is below the bottom edge of the hole, add oil through the filler hole to raise the level. 1) Filler hole 2) Drain hole 3) Oil level B00434 2