Oil Spec for '15 Legacy 4-cylinder engine outside of US

[saccpa]

I have a '15 Legacy with the 2.5L 4-cylinder, with 44K miles.  Per the US spec I have run 0w-20 synthetic since purchase in '15, with no issues (although I do think the engine is excessively loud at low RPMs).  I believe I have read that Subaru's oil spec for this engine in Japan, Europe, and elsewhere is 5w-30.  Can someone confirm this?  I am considering using 5W-20 or 30 in this engine, going forward, as I live in an area (middle TN) that does not get super cold in winter, and the 0W-20 seems excessively thin for my requirements.  The car sees an even mix of city and interstate mileage.  Thanks for your input!

[ammcinnis]

Are you driving your Legacy in "Japan, Europe, and elsewhere" conditions? If not, just stick with 0W-20 unless you're driving your car under exceptional conditions. 0W-20 is not "excessively thin" for normal street/highway driving.  Subaru knows what they're talking about.

That said, running 5W-30, even for an extended period, is unlikely to cause any harm. Your car, your choice.

 

[saccpa]

I understand your point, but it doesn't answer my question, which is: when the 2015 2.5L Legacy was introduced, what was the oil spec for that engine for cars sold in Europe and Japan? Thanks.

[XT-sub]

The following 'Technical forums > Oil, Oil Filters, and Fuel Discussion > Looking for oil info from outside N. America’ subaruoutback.org topic;

https://www.subaruoutback.org/threads/looking-for-oil-info-from-outside-n-america.514553/post-5877404

has some information on engine oil recommendations outside of North America.

In that topic I posted some information in posts #4 & #9 on the engine oil recommendations for the Australian spec vehicles (our vehicles are built in Japan). Our Liberty is the equivalent of the the US Legacy.

[saccpa]

Thank you, great thread!

 

[silverton]

Even the US 0-20 cars state in the manual that depending on climate, 5w30 is acceptable to use.

Edit: Okay, so I know I've seen on some car that 5w30 was acceptable that had the FB motor.  Looking up on alldata it shows the Forester only uses 0w20

Edited August 28, 2022 by silverton

[BoozeRS05]

Euro spec is 5w30 synthetic for the FB25

That’s all I run in my FB25 Forester, I will not use 0w20. It’s obvious btw the two in my car which will use more oil over 5k mile intervals. Only 5w30 synthetic for me, which brand I don’t care whatsoever.

Blackstone had no problem with it either, and I get 26-27mpg consistently with 167k miles currently.

[anthonyparra]

I think in north america, restrictions for emissions are getting really tight and since this generation Legacy is PZEV they tune the transmission and engine to always be on low rpms, and the thin oil is really just for the tune to take advatage of getting better gas milleage.

 

I have a 2016 Legacy 2.5i Limited and im still using 0w-20 with 112k miles, I will be tuning my engine soon though, so I will be making the switch to 5W-30 or 0W-40 since I will be revving the engine more.

[BoozeRS05]

I think you nailed it, standardizing 0w20 in North American is all about silly emissions restrictions and fuel efficiency marketing. It’s definitely not the “best” oil weight to use in my opinion for the FB25

[anthonyparra]

yeah, IMO it honestly all depends on the miles you have on the engine, the weather in your area, what you use your car for, and a bunch of other variables.

How different does your forester feel after making the switch? I hear there is less engine noise? does it feel more premium, if you know what I mean?

 

[BoozeRS05]

I’d say it’s nearly impossible to feel a difference in oil weight, but for my first oil change I did see oil moving down the dipstick around 1.5qts over 5k miles, compared to sometimes no oil loss with 5w30 in the same interval.

I’ve done a number of mods that give good results - larger brakes, lighter/wider wheels, sound deadening, steering dampener, suspension.. Different oil weight won’t make a noticeable driving experience in my opinion.

I’m pretty sure I get slightly better MPG with 87oct over 89oct. If I’m running a lot of grunt miles and it’s hot outside I’ll go with 89oct, but I still get 26-27mpg overall.