With appropriate tools and work space, routine car maintenance is a nice do-it-yourself experience. There are plenty of tutorials elsewhere for an engine oil and filter change, so I'll highlight some personal tips and vehicle specific information for a 2012 Subaru Impreza 2.0i 5-door.
- Engine Oil - SAE 0W-20 synthetic
- Capacity (Oil+Filter) - 5.0 quarts
- OEM Engine Oil Filter - Subaru P/N 15208AA15A
- Drain Plug Head - 17mm hex
- Drain Plug Gasket - 16 x 21 x 2.3mm crush washer, Subaru P/N 803916010
- Drain Plug Torque - 30.8 ft-lb
Tip #1: Roll down a window so you don't accidentally lock yourself out
Tip #2: Wheel chocks for safety! (Both directions.)
The oil filter and filler tube are located on the driver's side. The dipstick is on passenger side.
Tip #3: Wear gloves so you don't get burned and oily.
I undo the cap and filter first. I think the oil flows out faster by breaking the vacuum. I haven't done a scientific study, though.
The drain plug is under the driver's side. The skid plate has a cutout so you don't even have to remove any trim.
Last time I tried to get a gasket from a chain store, their database had incorrect dimensions for the drain plug. The engine oil pan drain plug is a 17-mm M16-1.5 flanged hex head. The OEM gasket is therefore 16mm ID. If someone gives you a 20mm, it will barely stay on the flange.
Tip #4: Secondary containment for your oil pan! I'm using a plastic tray.
Let the old fluid drain fully, then reinstall the drain plug with a new gasket. My trash service takes used oil and filters curbside, so I don't have to take it to a recycling center.
You should oil the new filter seal before installation. I also prime the filter with enough oil to wet the element so it won't be dry during start up.
I refill with a full 5 quarts of synthetic oil. Walmart and Amazon seem to have the best prices.
Since you're already in the engine bay, it's a good time to check the air cleaner element. The factory manual suggests removing the air scoop from the front of the air box. I find it easier to go from the back side, instead.
Undo the clamps and it should wiggle out easily. I've been buying aftermarket filters because it's all just paper anyway.
Since we're on the subject of filters, the cabin air filter is behind the glove box. Undo the dampener on the right side of the glove box, squeeze the hinge pins in towards each other, then swing the glove box down and pull out.
This one was pretty clogged. A new element seemed to improve air flow in the cabin. It smelled fresher, too.
Be sure to check fluid levels and watch for leaks after you're done. My Impreza seems to need about 1.5 quarts of top-off between oil changes (7,500 miles). Apparently, that's within specification. However, there are lots of internet stories about this FB20 engine. See Technical Service Bulletin 02-157-14R "Engine Oil Consumption" for details. Or, just Google "FB20 engine oil consumption" for some irate forum posts and YouTube videos.