I did the first oil change at 970 miles today.
Let me skip right ahead and let you know that I did not find any particles at the bottom of the drain bucket, and the oil still looked fine.
I bought a 5-quart jug, plus a single quart, of Mobil1 0W20 at Walmart.
I also had a Subaru 15208AA160 oil filter and a new crush washer (Subaru part number 803916010).
Here is the process:
1. The hotter the engine, the better will the oil drain, but be careful and do not burn yourself.
2. Pour some fresh oil in the new oil filter (into the center hole); lubricate the gasket on the filter with fresh oil; and set the filter aside to absorb the oil.
3. Pull the oil level dipstick slightly and loosen the oil cap so the air can get in when draining.
4. Put a bucket under the drain plug. Remove the drain plug (17 mm) and drain the oil. For cleaner start, you can slightly push the drain plug in as you are loosening it, and then when all the threads released pull the plug away in one motion.
5. While the oil is draining, you can loosen the oil filter, unscrew it and remove it slowly lifting up. Have a rug ready to catch any dripping oil. Hardly any oil came out when I did this today.
6. Wipe the filter mating surface of any debris. You can now screw in the new oil filter. The manual recommends tightening approximately one turn after the gasket contacts, torque spec 14 N.m (1.4 kgf-m, 10.3 ft-lb).
7. Get back under the vehicle, wipe the drain hole and its surroundings, and replace the drain plug with a new crush washer. Do not forget to remove the old crush washer, it may be stuck to ether the drain plug or to the oil pan, and may be hard to see due to being painted over. The drain plug torque spec is 41.7 N-m (4.3 kgf-m, 30.8 ft-lb).
8. If any oil got to any surfaces underneath the vehicle, clean it up. Hot exhaust is nearby. Make sure you do not forget any oily rugs there.
9. Refill with fresh oil.
10. Close the oil cap. Push the oil dipstick back in.
11. Start the engine to let the oil circulate for a bit.
12. Shut down the engine.
13. Check for leaks.
14. Check the oil level.
Now, let us talk about how much oil to put in. As you know, the manual says it is 5.3 quarts, when replacing oil and filter.
I put five quarts in today. And after checking, that was too much, I was about a quarter inch above the full mark on the dipstick.
Of course it depends on how much old oil you manage to drain. I drained slightly over five quarts of factory oil, plus whatever was in the old filter, meaning my Subaru was overfilled even more at the factory. So, I think 5 quarts is plenty, you do not really need to buy six.
I put the extra little bottle in the recessed area in the caddy above the spare tire, it fits there nicely.