2021 - Limited - Oil Drain Plug Size?

TTiimm · 2025-10-07T16:16:52-0400

Botnik said:
I could get only one arm onto the ratchet for the drain bolt. ... having only one hand on the ratchet usually leads to the socket not being on the drain bolt properly/fully, leading to wear/damage to the bolt.

Try a long handled box wrench.

Botnik · 2025-10-07T16:54:27-0400

TTiimm said:
long handled box wrench.

I changed the oil a couple days ago and am not under there right now but I think a box wrench would need to have a bend in it, because the bolt is so far in, and then when you flipped the wrench over to go in the other direction, the bend would be the wrong way. So I’d need to find my wrenches that don’t have ratchets in them. Anyway I’d still need to slide in enough so I could see what I’m doing. I’ll check again in about 10,000 km.

j3rf · 2025-10-07T19:43:50-0400

Don't like using 12 point box end wrenches on a sometimes already problematic drain plug.

6 point shallow 14/17MM socket, 3/8 drive ratchet with some length (my dedicated oil drain plug ratchet is 13" overall). I find a non-flex head ratchet more reliable than one with a flex.

DragonSubie7 · 2025-10-07T20:05:32-0400

With a drain valve the tool discussion is a moot point.
You don't need any tools to drain the oil after it's installed.

TTiimm · 2025-10-07T21:01:29-0400

Clearly a long handled box wrench is superior.

With the right box wrench, I can have that oil change turned around and the next billable customer on the rack before my competition... eh.... er.... coworkers have their sockets clipped in.

I'm not interested in the geometry of the drain plug when I'm done. That's for the engineers. As long as the card reader says "approved" then I'm good. Neeext!

And a man comes on and tells me

How white my shirts can be

Well, he can't be a man 'cause he doesn't use

The same drain plug wrench as me

I can't get no. No no no.

Hey hey hey. That's what I say.

The days of using manuals are gone. I look up how to do oil changes on AI.

j3rf · 2025-10-07T22:01:06-0400

Don't forget your loctite no one removes drain plugs anyways!

Fibber2 · 2025-10-08T00:24:22-0400

For future reference: The current Subaru oil filter is 15208AA21A. The 20A left the building early this year.....

deeveebee · 2025-10-08T10:21:55-0400

Fibber2 said:
For future reference: The current Subaru oil filter is 15208AA21A. The 20A left the building early this year.....

The OEM filter that came on my ‘23 is 15208AA160. It’s the black one made by Tokyo Roki. I’ve been able to acquire these since 2023 and still have a few in inventory. Is the 15208AA21A the official OEM replacement?

2017SubeNewb · 2025-10-08T10:54:41-0400

Botnik said:
I changed the oil a couple days ago and am not under there right now but I think a box wrench would need to have a bend in it, because the bolt is so far in, and then when you flipped the wrench over to go in the other direction, the bend would be the wrong way. So I’d need to find my wrenches that don’t have ratchets in them. Anyway I’d still need to slide in enough so I could see what I’m doing. I’ll check again in about 10,000 km.

I have one (not the right size for Sube oil change, albeit) straight ratcheted wrench with offset bends on both ends - 2 dif "socket" sizes. Ratchet direction is changeable on/off with a flick of a small toggle on either end. Think it was from Sears be4 they closed down. So they do make (made?) them. FWIW - I had to use my Makita driver to loosen the plug on my 1st oil change last weekend. It was on way too tight. Torqued it back in place when I was done. 14mm plug.

TTiimm · 2025-10-08T11:04:35-0400

I read that Subaru was painting the oil pans with the drain plug installed. This made the plug difficult to remove on the first oil change.

Not sure where I read this or how true it is.

j3rf · 2025-10-08T11:23:46-0400

They do paint them, but don't find first oil change drain plugs any tougher than other ones.

Botnik · 2025-10-08T18:43:55-0400

Fibber2 said:
The current Subaru oil filter is 15208AA21A. The 20A left the building

I changed my oil the other day. The filter I took off was a 15A, the last one I had. Into the 21A filters now.

SF Ex-Pat · 2025-10-08T19:35:19-0400

deeveebee said:
FWIW, oil changes on a Forester can be an entirely tool-free, jack-free, ramp-free endeavor. They are for me, anyway, and I have ALL the tools. Just get an oil drain-plug valve -- whichever model you prefer. I got a Valvomax, which I highly recommend, but any reputable option is better than the standard drain plug. I'm a fairly large human, and I can get my head and arm under the Foz easily enough to rotate the hinged plastic oil-drain cover out of the way, unscrew the Valvomax cap, and then screw on the Valvomax drain tube, all WITHOUT needing to lift the vehicle (granted I'm usually working on a clean garage floor). It honestly couldn't be easier, and zero tools are required.

I've been working on cars for 30+ years and IMO the Valvomax (or equivalent) is the single best DIY mod you can make.

I second the Valvomax. I’ve put them on my Forester and two Hondas in my family.

NewEngland · 2025-10-09T04:39:55-0400

After I used up my dealer oil changes, I purchased the recommended 17mm replacement plug. During my first change I was surprised to see the dealer had already switched the plug without ever mentioning it. Next change I put in a Fumoto Valve.

2021 - Limited - Oil Drain Plug Size?

TTiimm

Botnik

j3rf

DragonSubie7

TTiimm

j3rf

Fibber2

deeveebee

2017SubeNewb

TTiimm

j3rf

Botnik

SF Ex-Pat

NewEngland

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