Oil Weight Question(s):

[Button]

To All,

Hello. I just wanted to introduce myself. My name is Button & I've been reading the forum for years but never registered until tonight!

Nevertheless, I have an '06 Subaru 2.5i OBWL w/ roughly 51K miles. I've been using AMSOIL Signature Series since 3K & have experience slight oil consumption 1/4 Qt per 600 miles.

Do y'all think I should try 5w30, 10w30, 10W-40 &/or 5W-40 to curb consumption? Would changing from 0w30 to something else help?

Regards,
~Button

 

[bustednutz]

Whats an OBWL?

 

[Button]

So sorry. Outback Wagon Limited.

 

[Gary Allan]

I'll venture an Outback

I'd check the PCV system.


Ooops ..beat me to it (looking at another page with the reply window open).

 

[bustednutz]

Are there any leaks that you know of?

 

[Button]

No leeks. I owned 4 Subaru's & they all seem to use some oil between changes.

 

[Gary Allan]

Oh ..I misread your post. You've been using it all along at that rate. I'd still see if there's some flaw in the PCV system ..even on the design level.

Have you ever done a used oil analysis? A quart every 2400+/- ..it's not bad ..but I'd surely want better.

The way you describe it the consumption is flat/linear. That means it's not an oil fatigue issue (hard to do with SSO).

How far do you run SSO out?

used oil analysis with this engine show no consumption even over 10k and w/turbo.

 

[Button]

Gary,

I follow Amsoil OCI using Ea Filter. I change my air filter 1 a year. The consumption falls in the parameters of what's acceptable per Subaru but I'd like to decrease it if possible. I didn't know if changing the viscosity will help?

~Button

 

[Pop_Rivit]

Consumption that slight is nothing to be concerned with-especially with a boxer engine. You're talking a quart in 2400 miles.

Isn't 5w30 the recommended weight? In our 2005 OBS with the 2.5 it is. I tried 5w-20 once and consumption increased. I run 5w30 and use about a quart every 5,000 miles.

 

[tig1]

Try a 5-40. A qt. of Ams every 2400 miles gets pricey very quick.

 

[Gary Allan]

It might. I was just comparing it to what I found on site in the used oil analysis section.

An increase in viscosity may relieve the issue. SSO is 10.3 Cst @ 100C. Both the 5w30 (ASL) and 10w30 (ATM) are 10.8 Cst ..so you're not gaining anything. If you want to stay in a 30 range, HDD 5w30 is 11.3 Cst. It's the same cost as SSO. It's virgin TBN is a tick lower ...but you're not going to trump that with the 16k+/- per year you're running at.

 

[Button]

Gary,

So sorry but your verbiage just went over my head. The viscosities between SSO, 5w30 & 5W-40 are almost the same? You recommend HDD 5w30?

Thanks,
~Button

 

[Button]

Let me just throw it out there? What about 10W-40? It's OK per the manual & we don't that many freezing temps in GA?

 

[Pablo]

Going to an XW-40 may help a bit. I doubt changing to another XW-30 will help.

 

[Gary Allan]

Sure, if you want to use a 40 weight. The AMO (10w-40) is about midrange in the 40 grade. It would probably settle if viscosity can relieve the consumption or not. It will also handle your mileage on an annual OCI.

I'd like to see a used oil analysis of this fill ..but I can't pull anything out of my behind that would be altered or altering to the oil to make straight line consumption right off the bat.

 

[Button]

To All,

Last question . . . which oil would you suggest?

Thanks,
~Button

 

[Gary Allan]

Originally Posted By: tig1
Try a 5-40. A qt. of Ams every 2400 miles gets pricey very quick.


That was my thought too. Not that it amounts to a whole lot annually, but he's got amost 2 sumps in make up.

 

[c3po]

Originally Posted By: Button
To All,

Last question . . . which oil would you suggest?

Thanks,
~Button


If you are having a problem with the PCV system you will continue to have some oil consumption problems, check the PCV hose and the PCV Valve and stick with your current oil or whatever grade of oil is recommended in your owner's manual.

 

[friendly_jacek]

I understand that changing oil brands and base groups can change consumption. I personally had no oil consumption in Subaru's 2.5L H4 with 5w30 conventional oils and 5W40 group III.

 

[yannis]

Originally Posted By: Button
Let me just throw it out there? What about 10W-40? It's OK per the manual & we don't that many freezing temps in GA?

That's the correct answer. Mobil makes a good one.