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2012 Ice Silver 2.5i Limited
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Discussion Starter · #1 ·
I'm torn on whether to switch from using regular oil to synthetic. The one advantage I see is less trips in for an oil changes - 3750 miles (severe condition) to 7500 miles. Thoughts, please.
 

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2012 Subaru Outback 2.5i Limited
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Yeah, but you still have to change the oil filter...so, why waste money? Are you really in the "severe" category? For me, it is 7500 miles intervals. And at that interval, there is no need for synthetics.
 

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2011 Outback Premium 2.5i CVT, '13 BRZ Limited
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I use synthetic, when I have to swap the filter I drive it up on a ramp, drain the oil through a fumoto drain valve into a 5L jug, swap the filter, and pour the oil back in. It's a money saver in the end.
 

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2010 Outback
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10 Posts
I have used Mobil 1 since day 1. Believe I get better mileage. Average 27-28 mpg, can get upwards of 31-33 mpg on highway, depending on wind, AC, etc.
 

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Opinions on oil threads are like asking about your favorite brand of beer.
Opinions are like belly buttons, we all have one.
Modern motor oils are all good.
 

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2012 Subaru Outback 2.5i Limited
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I have used Mobil 1 since day 1. Believe I get better mileage. Average 27-28 mpg, can get upwards of 31-33 mpg on highway, depending on wind, AC, etc.
Same mileage with conventional for me.
 

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2011 Tacoma TRD Sport Double Cab Long Box
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I have used Mobil 1 since day 1. Believe I get better mileage. Average 27-28 mpg, can get upwards of 31-33 mpg on highway, depending on wind, AC, etc.
I've run both Mobil1 0w-30 Full Synthetic in my 2004 and Conventional 5w-30 (different brands) and have never noticed an MPG difference. Mobil does advertise it as helping fuel economy, but it's probably such a slight difference that you'd have to track it over a long time to notice.
 

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2012 limited, white, no moonroof or nav
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I guess I am in the minority.......I use synthetic in everything I own that was built since 1950. It stays in grade longer, and works better when it gets hot, and reduces temps in air cooled motors. The difference in cost is minimal, to my way of thinking. With the OB, I will be changing the oil at the required 7500 miles, or sooner if I feel like it. (I generally use 5k changes for most of my vehicles, partly because it is very easy to keep track.)

That said, as long as you actually change the oil and filter according to Subaru's schedule, any oil that meets grade requirements will keep you from experiencing any lubrication related failures.
 

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2016 Carbide Gray Limited with Moonroof, Nav, and Eyesight
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906 Posts
If you live where it gets to over 100F in the summer and down to -25F (and colder) in the winter like I do the synthetic just gives me peace of mind. And then I just run it 6 or 7 thousand miles instead of 3 to 4 thousand and the cost is a wash.
 

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2012 Subaru Outback 2.5i Limited
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IMO, oil changes every 3-4k miles is wasteful. There was an article a while back (link no longer working), but this is what it concluded:

"Based on the results we've got here, we'd recommend 8,000 miles between oil changes on an engine that uses no oil at all, perhaps 10,000 miles on an engine that uses some oil, and 15,000 miles or beyond with a filter change every 5,000 miles. This, of course, isn't any kind of guarantee, and you must evaluate for yourself what your engine requires. One thing we're pretty sure about though: 3,000-mile intervals is a huge waste of resources."

NOTE: this is for Mobil 1 Synthetic. My opinion is that if you're gonna change every 8k miles, then why use synthetic at all?
 

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2012 Subaru Outback 2.5i Limited
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Engine wear actually decreases as oil ages. This has also been substantiated in testing conducted by Ford Motor Co. and ConocoPhillips, and reported in SAE Technical Paper 2003-01-3119. What this means is that compulsive oil changers are actually causing more engine wear than the people who let their engine's oil get some age on it.
 

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Engine wear actually decreases as oil ages. This has also been substantiated in testing conducted by Ford Motor Co. and ConocoPhillips, and reported in SAE Technical Paper 2003-01-3119. What this means is that compulsive oil changers are actually causing more engine wear than the people who let their engine's oil get some age on it.
Link?
 

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2012 Subaru Outback 2.5i Limited
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Sorry, you gonna have to google it. The article is old and is archived.

BUT, i wonder if the article may have swayed OEMs into prolonging the oil change intervals on newer powertrains.
Hate to quote myself, but there is some controversy in interpreting that SAE article:

"This is a gross miss-representation of what SAE Technical Paper 2003-01-3119
determined. The title of the paper is - "Antiwear Performance of Low
Phosphorus Engine Oils on Tappet Inserts in Motored Sliding Valvetrain Test"
The test was a pure wear test using externally driven valve train
components. A complete engine was not involved. There was no dilution of the
oil by blow-by, no combustion products added to the oil, and no water added
to the oil. The results might matter if you are building a sealed machine
driven by an electric motor, but trying to claim this paper is a basis for
extending oil change intervals is not reasonable."
 

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2016 Carbide Gray Limited with Moonroof, Nav, and Eyesight
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IMO, oil changes every 3-4k miles is wasteful. There was an article a while back (link no longer working), but this is what it concluded:

"Based on the results we've got here, we'd recommend 8,000 miles between oil changes on an engine that uses no oil at all, perhaps 10,000 miles on an engine that uses some oil, and 15,000 miles or beyond with a filter change every 5,000 miles. This, of course, isn't any kind of guarantee, and you must evaluate for yourself what your engine requires. One thing we're pretty sure about though: 3,000-mile intervals is a huge waste of resources."

NOTE: this is for Mobil 1 Synthetic. My opinion is that if you're gonna change every 8k miles, then why use synthetic at all?
This may well be true, although the owners manual suggests more conservative changes, and base their warranty on following maintenance guidelines. I feel short trips in extreme temps are "severe service".

1st oil change all models recommended at 3 mos or 3000 miles whichever comes first. Required on 6 cylinders. 2.5L required at 7,500 miles or 7 mos.
Oil Changes: 3,750 mile oil changes, or at every 7,500 miles under very easy driving conditions
 

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2012 Subaru Outback 2.5i Limited
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2011 Tacoma TRD Sport Double Cab Long Box
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Here is a good link for further discussions: Compulsive Oil Changers Cause More Engine Wear

And for synthetic fans, here is a long article for your reading pleasures: http://www.mr2.com/TEXT/synth_oil.txt

Yup, that's the extent of my limited knowledge on the matter...you guys can read and decide. For me, even in Texas heat, i am sticking to 7500 mile intervals with regular oil.
Hmmm...that's interesting.

When I ran Synthetic, I often found I'd be changing it at around 4000 miles to do it just before the winter (to avoid changing it again in the cold--it would last until spring). So, I decided it was probably pointless to be running synthetic oil (might run it in the winter for the 0w attribute).

I've been sticking to ~4000 mile intervals with conventional oil since I fit some of the definitions of severe service (but not consistently or all the time). Maybe I should push that a little further back.
 

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2012 Subaru Outback 2.5i Limited
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I may go to 5000 interval after warranty period only because it is easier for my mind to do the math! :D
 
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