Best time interval to change my oil?

Well, it's gonna be that time where I need to replace my serpentine belt, and eventually do my oil change (at least I think). I've got $20 off an oil change, but I've driven my car 6 months since the last change and I'm coming up on 3800 miles since the last change. Is it best for me to just wait till around 5000 miles, or should I just do the oil change when getting my new serpentine belt? I'm probably gonna try to get the belt changed this upcoming weekend, not sure if I'll do it at Firestone or the Subaru Dealership. Thanks for the help! Edited October 23, 2019 by Alexmed2002

i change mine around 3500 with a full synthetic and OEM filter. it's cheap enough that doing it a little early is better for my peace of mind than running the oil til the ragged edge and possibly doing engine damage.

 

also, if you're mechanically inclined at all, an oil change and new serpentine belt are both very, very easy, and the tools to do it(minus a jack and jack stands) will cost you less than having both of those things done at the dealership or a quick oil change place

The factory service interval is 8 month or 7500 miles. I changed the oil on my 2.5i at 7500 miles and my Blackstone oil sample came back good. Just remember to check your oil.

 

My Legacy GT oil samples didn't look good at 5000 miles, but look good at 3750, so that is the interval I am doing.

I would be ok doing 7500 on an NA, otherwise don't waste money on synthetic.

i change mine around 3500 with a full synthetic and OEM filter. it's cheap enough that doing it a little early is better for my peace of mind than running the oil til the ragged edge and possibly doing engine damage.

 

also, if you're mechanically inclined at all, an oil change and new serpentine belt are both very, very easy, and the tools to do it(minus a jack and jack stands) will cost you less than having both of those things done at the dealership or a quick oil change place

 

I got the belt replaced today at the local Firestone near me, they're great over at the shop I go to. They've done work for me on my old truck before I sold it, so I trust them. Cost $132 but that's because the belt was just under $60. I don't have anywhere to work on my car so I didn't have much of a choice, but it's nice to have the peace and mind of knowing my belt won't snap into pieces. It hasn't been replaced for many, many miles. Sometimes in the morning it would squeal so loud and scared the living heck out of me

I would be ok doing 7500 on an NA, otherwise don't waste money on synthetic.

 

I always use synthetic on my vehicles if I can. I was reading up that Subaru changed their recomendation on oil changes for my engine to 6,600 miles or something like that. I'll probably just do it every 5,000 miles so that I won't be feeling worried.

go in every 6.5K or 6 months, whatever comes first

So Subaru says first change at 3k, second at 7500 miles, then once every 7.5 months/7500 miles after that, unless you do lots of short trips, live in a very cold area, or do repeat trailer towing, then it's every 3.75 months/3750 miles. They don't require synthetic for the 2.5i (at least in 2013), but synthetic is always preferable to me (while folks debate whether or not it's necessary, synthetics are superior lubricants pretty much any way you look at them)

 

 

to answer your question, you are absolutely fine waiting if that's what you want to do.

 

 

(other engines, like the EJ25T are different in that synthetic is required (at least for 2012+) and they are harder on the oil - I change mine every 3k miles give or take a little, always with a high quality synthetic)

Our Ascent is 6months/6k miles for every change including the 1st.

 

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If you have an oil in mind, try google for UOA's of it in your car model or one with a similar engine.

 

Since I have a GT when I see an interesting oil I google for UOA's of it in pre-'15 WRX's or STI's.

 

Of course location and driving habits will factor in heavily but gives a good actual place to start.

Our Ascent is 6months/6k miles for every change including the 1st.

Subaru is just weird - they seem to have different intervals on different cars with the same engine, etc. - the 15+ WRX/STi sounds similar to the Ascent - it's still first at 3k/3 mos, second at 6k/3 mos, then it's 6k/6 mos after that... but in 2014, it was the 3k, 4.5k, then 7.5k after that... you'd think well, maybe that's because of the FA20, but the same thing holds for the EJ25 in the STi, which has been around for a while...

Subaru is just weird - they seem to have different intervals on different cars with the same engine, etc. - the 15+ WRX/STi sounds similar to the Ascent - it's still first at 3k/3 mos, second at 6k/3 mos, then it's 6k/6 mos after that... but in 2014, it was the 3k, 4.5k, then 7.5k after that... you'd think well, maybe that's because of the FA20, but the same thing holds for the EJ25 in the STi, which has been around for a while...

 

 

Maybe it’s because the newer ones call for so much thinner oil? My ‘97 Outback with a Phase II EJ25D called for natural 10W30 or 5W30 every 7500mi, while my EJ253 ‘05 Forester took natural 5W30 every 7000, though you had to throw a quart in every 2500mi to keep up with the leaking oil cooler seal.

 

The newer motors all have shorter intervals: the FB25B in my wife’s ‘18 Forester takes synthetic 0W20 every 6k, as does the FB20D in my MIL’s Crosstrek. The ‘13 EZ36D I’ve got now is supposed to take natural 5W30 every 6k. They specifically say you can use synthetic, but you should use the same interval. The sixes are probably outliers, though.

 

Actually, thinking back on it, the older motors all used or leaked a bunch of oil. They’re probably leaning on the fact that you’ve gotta put in a quart or two between changes, so you’ve got fresh stuff in there and can go a little longer...

 

Wanna see some crazy shit? Look at some German cars from the early ‘00’s. I’ve got an ‘02 BMW that takes synthetic 5W30 every 15k. You bet your ass I change it more frequently than that!

 

 

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The factory service interval is 8 month or 7500 miles. I changed the oil on my 2.5i at 7500 miles and my Blackstone oil sample came back good. Just remember to check your oil.

 

My Legacy GT oil samples didn't look good at 5000 miles, but look good at 3750, so that is the interval I am doing.

 

Factory oil service interval for turbo models is actually 3750. http://www.cars101.com/subaru/subaru_maintenance1.html

 

Also in 2011 Subaru started declaring turbo models must use synthetic. It's highly recommended for a 2010 LGT as well.

Factory oil service interval for turbo models is actually 3750. http://www.cars101.com/subaru/subaru_maintenance1.html

 

Also in 2011 Subaru started declaring turbo models must use synthetic. It's highly recommended for a 2010 LGT as well.

 

The 7500 interval was in reference to his 2.5i.

 

With the addition of the synthetic oil, Subaru also changed the oil change interval to 7500 miles in 2011 for the turbo models. I wouldn't recommend this though, my car's oil samples didn't like the extended miles with synthetic oil.

The 7500 interval was in reference to his 2.5i.

 

With the addition of the synthetic oil, Subaru also changed the oil change interval to 7500 miles in 2011 for the turbo models. I wouldn't recommend this though, my car's oil samples didn't like the extended miles with synthetic oil.

 

For my own sake I think I'll stick with every 8 months/5,000 miles. Not going to wait too long, but I also don't want to change my oil too often.

The 7500 interval was in reference to his 2.5i.

 

With the addition of the synthetic oil, Subaru also changed the oil change interval to 7500 miles in 2011 for the turbo models. I wouldn't recommend this though, my car's oil samples didn't like the extended miles with synthetic oil.

 

I forgot about the schedule change to the 2011 GT but there are a couple notes that basically point out Subaru admitting 7500k is too long for these kind of engines when turbo'd with the engine oil being supplied to the turbo bearing.

 

Subaru owner's manual maintenance schedule

> Early warranty books: the Subaru maintenance schedule note #1 reads "When the vehicle is used under severe driving conditions, the engine oil and filter should be changed every 3,750 miles or 3 3/4 months. All turbo-charges vehicles are considered to be operated under severe driving conditions"

> Later warranty books: the statement no longer includes All turbo-charges vehicles are considered to be operated under severe driving conditions.

Suggested: do the first oil change by 3mos or 3000 miles and then at least a minimum of every 7500 miles or 7.5 months afterwards. That is as long as you should go and it is strongly recommended to replace it much more frequently.

 

With your 2.5i you'd be fine with 7500 especially if you don't race it around all the time. The higher frequency oil changes are suggested for the turbos because the journal bearing is sensitive to oil wear and has a tendency to destroy oil. One newer models they bumped the schedule down from 7.5 to 6.

IIRC during the time Subaru was using dino oil, they eventually started recommending the severe service 3750 interval for the turbo cars.

 

The return to standard 7500 interval was probably in conjunction with the recommending of synthentic for the turbo models.

 

With the woefully low 4 or so qt capacity, hot turbo, and enthusiastic driving, the turbo motors can be really hard on oil. Euro cars with cross continent high speed touring in mind will have almost double the oil capacity and so more oil to deal with harsh conditions.

 

UOA's are a pain for me so I just change at the old severe service interval of 3750 or around there. Most UOA's I've seen show this as a safe interval, if a bit conservative.

 

NA motors seem to be a lot easier on oil from what I've read so I would have no problems sticking with the standard interval on it even with a good conventional oil, IMO.