15 Forester 0w-20 or 0w-30 ok per Mobil 1 site?

GravelRoad · May 30, 2015

Hello! Been lurking daily for 9+ years. Just Joined.

My 2015 Subaru Forester 2.5i 6spd that was purchased 4/14 says to use 0w-20 synthetic only in the owners manual.

When first purchased I checked the Mobil 1 oil site. It also said 0w-20. Just check the site a few days ago, site has changed.

Now it says: "Based on what you've told us, your vehicle manufacturer recommends a 0W-20 viscosity and synthetic oil. A 0W-30 viscosity can also be used. We offer these motor oils to help protect your vehicle."

My oil temp per the Forester readout (and my Edge CTS) has hit as high as 230F on the hottest day. A/c was on traveling 75mph up a 2 mile grade.
I would say my average 1 year warmed-up oil temp 216F.
My 6spd turns 2750rpms at 70mph. I have read (on the Forester forums) that the CVT turns 2200rpms at 70mph.

So my questions: Why does Mobil 1 say I can use 0w-30? Should I stick with 0w-20 year around? Use 0w-30 in summer and 0w-20 in winter? 0w-30 year around? Does it matter?
Really like this vehicle and want to keep it until the wheels fall off.

Your thoughts?

simple_gifts · May 30, 2015

I'd use what the manufacturer warranting the vehicles says.

Shellguy · May 30, 2015

Id just run mobil 1 0w20 ep and call it a day if i were you.

GravelRoad · May 30, 2015

Originally Posted By: Shellguy
Id just run mobil 1 0w20 ep and call it a day if i were you.

Thank you. I change oil every 5k. First change was 1.5k (made the early feel-good change
) Second 2 were Mobil 1 AFE 0w-20. Last 2 were Mobil 1 EP 0w-20. All with oem filters.

Run about 20k a year. Subaru calls for max 6k changes. Mostly interstate driving. 5k oil changes is easy to remember.

JTK · May 30, 2015

What site are you referring to that says 0w30 is fine?

Subaru is pretty adamant on the 0w20 recommendation. I don't recall it saying it's a requirement, and I own a 2014 XV Crosstrek that has the 0w20 recommendation. I think this is a fine oil, just can be tough to find and overpriced. FWIW, I currently have 5w20 in my Subaru.

geeman789 · May 30, 2015

My Subaru, from back in the old days ... 2011 lol, recommends oil based on ambient temps and operating conditions... who'd have thunk...!

Anyway, it says use 5w30 for best fuel economy, BUT also shows 10w30, 10w40 , straight 40 ??? and even 20w50 as being acceptable... the 20w50 is for operation in very hot temps or heavy duty useage (not sure exactly what that is... aside from racing.)

Thicker oil will definitely not hurt your car... and moving up to a 30 grade, or even a 40 may be appropriate given your oil temps.

The only issue is the dreaded "what about your warranty ... " question. Subaru now states that only 0w20 is recommended. If you do run a thicker oil, and have an engine issue while under warranty, only then will you find out if it is going to be a problem...

Or, buy 0w20, keep copy of receipt, return it and run whatever oil you like... I didn't say that, did I...?

GravelRoad · May 30, 2015

Originally Posted By: JTK
What site are you referring to that says 0w30 is fine?

Subaru is pretty adamant on the 0w20 recommendation. I don't recall it saying it's a requirement, and I own a 2014 XV Crosstrek that has the 0w20 recommendation. I think this is a fine oil, just can be tough to find and overpriced. FWIW, I currently have 5w20 in my Subaru.

Just go to Mobiloildotcom and click "Find the right oil".

If you have the non-hybrid 2.0 it also says 0w-20 or 0w-30.

GravelRoad · May 30, 2015

Originally Posted By: JTK
What site are you referring to that says 0w30 is fine?

Subaru is pretty adamant on the 0w20 recommendation. I don't recall it saying it's a requirement, and I own a 2014 XV Crosstrek that has the 0w20 recommendation. I think this is a fine oil, just can be tough to find and overpriced. FWIW, I currently have 5w20 in my Subaru.

From my owners manual:

0W-20 synthetic oil is the required oil
for optimum engine performance and
protection. Conventional oil may be
used if synthetic oil is unavailable.
*: If 0W-20 synthetic oil is not available,
5W-30 or 5W-40 conventional oil may
be used if replenishment is needed but
should be changed to 0W-20 synthetic
oil at the next oil change.

Per a different chapter:

Engine oil viscosity (thickness) affects
fuel economy. Oils of lower viscosity
provide better fuel economy. However,
in hot weather, oil of higher viscosity is
required.

I assume for "optimum engine performance" it's required. Or is it "in hot weather, oil of higher viscosity is
required"?
And what is this mysterious viscosity they speak of in hot weather. How hot is hot weather?

Silly manual.

HTSS_TR · May 30, 2015

I would use synthetic 0W20 during warranty, after warranty I would use M1 0W20 EP with 1 or 2 quarts M1 0W40 to raise HTHS a little for summer driving.

901Memphis · May 30, 2015

I would use the Mobil 1 AFE 0w30 in this situation.

147_Grain · May 30, 2015

Originally Posted By: 901Memphis
I would use the Mobil 1 AFE 0w30 in this situation.

+1

0W-20 synthetic in the winter and 0W-30 in the summer.

Donald · May 30, 2015

I have the same vehicle/engine and changed it at about 2200 miles to 0W20 PP. I have the CVT model.

If Subaru feels the engine will be properly lubricated with 0W20 I am fine with that oil weight.

BrianC · May 30, 2015

Originally Posted By: 901Memphis
I would use the Mobil 1 AFE 0w30 in this situation.

No need to split hairs. In Virginia, 0w-30 is a good choice year round.

Rand · May 30, 2015

0w20 is fine if you don't junk it up with MMO, or other unnecessary additives/solvents etc.

There is actually very little difference between m1 ep 0w20 and m1 afe 0w30

usually
about 20% thicker not the 50% you would assume

Revving2Redline · May 30, 2015

I'd go 0w30 and 0w20 during winter. 30wt just makes me feel better but them pushing a full syn 0w20 is good too.

geeman789 · May 30, 2015

Originally Posted By: GravelRoad
Originally Posted By: JTK
What site are you referring to that says 0w30 is fine?

Subaru is pretty adamant on the 0w20 recommendation. I don't recall it saying it's a requirement, and I own a 2014 XV Crosstrek that has the 0w20 recommendation. I think this is a fine oil, just can be tough to find and overpriced. FWIW, I currently have 5w20 in my Subaru.

From my owners manual:

0W-20 synthetic oil is the required oil
for optimum engine performance and
protection. Conventional oil may be
used if synthetic oil is unavailable.
*: If 0W-20 synthetic oil is not available,
5W-30 or 5W-40 conventional oil may
be used if replenishment is needed but
should be changed to 0W-20 synthetic
oil at the next oil change.

Per a different chapter:

Engine oil viscosity (thickness) affects
fuel economy. Oils of lower viscosity
provide better fuel economy. However,
in hot weather, oil of higher viscosity is
required.

I assume for "optimum engine performance" it's required. Or is it "in hot weather, oil of higher viscosity is
required"?
And what is this mysterious viscosity they speak of in hot weather. How hot is hot weather?

Silly manual.

That's code for ... "CAFE says I must recommend only the oil grade used in mileage testing, even though thicker oil MIGHT be more appropriate under certain conditions..."

A case of READ BETWEEN THE LINES...!

GravelRoad · May 30, 2015

Thanks everyone! Looks like a 50/50 split.

901Memphis · May 30, 2015

Originally Posted By: geeman789
Originally Posted By: GravelRoad
Originally Posted By: JTK
What site are you referring to that says 0w30 is fine?

Subaru is pretty adamant on the 0w20 recommendation. I don't recall it saying it's a requirement, and I own a 2014 XV Crosstrek that has the 0w20 recommendation. I think this is a fine oil, just can be tough to find and overpriced. FWIW, I currently have 5w20 in my Subaru.

From my owners manual:

0W-20 synthetic oil is the required oil
for optimum engine performance and
protection. Conventional oil may be
used if synthetic oil is unavailable.
*: If 0W-20 synthetic oil is not available,
5W-30 or 5W-40 conventional oil may
be used if replenishment is needed but
should be changed to 0W-20 synthetic
oil at the next oil change.

Per a different chapter:

Engine oil viscosity (thickness) affects
fuel economy. Oils of lower viscosity
provide better fuel economy. However,
in hot weather, oil of higher viscosity is
required.

I assume for "optimum engine performance" it's required. Or is it "in hot weather, oil of higher viscosity is
required"?
And what is this mysterious viscosity they speak of in hot weather. How hot is hot weather?

Silly manual.

That's code for ... "CAFE says I must recommend only the oil grade used in mileage testing, even though thicker oil MIGHT be more appropriate under certain conditions..."

A case of READ BETWEEN THE LINES...!

Yes i agree with this, the manual clearly leads you to a thicker grade.

bluesubie · Jun 1, 2015

Originally Posted By: 901Memphis
Originally Posted By: geeman789
Originally Posted By: GravelRoad
Originally Posted By: JTK
What site are you referring to that says 0w30 is fine?

Subaru is pretty adamant on the 0w20 recommendation. I don't recall it saying it's a requirement, and I own a 2014 XV Crosstrek that has the 0w20 recommendation. I think this is a fine oil, just can be tough to find and overpriced. FWIW, I currently have 5w20 in my Subaru.

From my owners manual:

0W-20 synthetic oil is the required oil
for optimum engine performance and
protection. Conventional oil may be
used if synthetic oil is unavailable.
*: If 0W-20 synthetic oil is not available,
5W-30 or 5W-40 conventional oil may
be used if replenishment is needed but
should be changed to 0W-20 synthetic
oil at the next oil change.

Per a different chapter:

Engine oil viscosity (thickness) affects
fuel economy. Oils of lower viscosity
provide better fuel economy. However,
in hot weather, oil of higher viscosity is
required.

I assume for "optimum engine performance" it's required. Or is it "in hot weather, oil of higher viscosity is
required"?
And what is this mysterious viscosity they speak of in hot weather. How hot is hot weather?

Silly manual.

That's code for ... "CAFE says I must recommend only the oil grade used in mileage testing, even though thicker oil MIGHT be more appropriate under certain conditions..."

A case of READ BETWEEN THE LINES...!

Yes i agree with this, the manual clearly leads you to a thicker grade.

If the OP contacted Subaru of America they would very likely advise to stick with 0W20, regardless of all of the contradictory language in the manual.

In Japan, no worries running an ACEA A3/B3 0W30.

http://www.pleiades-zero.com/?page_id=2

FutureDoc · Jun 1, 2015

Use 0w20 for the warranty period. Don't bother with Mobil EP as it will be wasted with the 6K intervals (unless you want that warm fuzzy feeling for running on unicorn tears). Run the oil that you like and as cheap as you want (I say Napa Syn 0w20 is very good for a 6K change). It was previously spec-ed at 7.5K before those who never checked oil freaked out about that new-fangled oil level light.

You can add a thicker oil for "top off" but if you start off with a thicker grade, you might give Subaru wiggle-room on any warranty claims.

No-where in VA is increasing the viscosity needed for this application... save for a few miles here and there like VIR and such. You can drive (my family route) from Shenandoah, to Russell Co, from the RVA and all the way out to Princess Anne with 0w20... even in the DC and VaBeach traffic. Despite the feel, VA is not the American SW in temp where those manual claims might hold some weight.

15 Forester 0w-20 or 0w-30 ok per Mobil 1 site?

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