Synth Oil Question

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Well guys, this has prolly been answered and it's a Subaru oil question, but the guy's input I want usually frequent here (apologies to the mods).

I picked up a 1999 Subaru Forester, non-turbo, 2.5L engine for my wife and as a 2nd vehicle. It has had synthetic oil all of it's life (149k miles, bah!) If I change it over to conventional, any real harm in this? I have heard everything from it eating bad seals to harming engine surfaces. I know it's probably bunk info, but wanted to get some input anyways. Thanks!
 
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yeah, could do that too. I already do 7k intervals. maybe go to 10k? I think it's the only way synthetic makes sense. Conventional is getting up there.
 
NA Subaru engines are pretty easy on oil.

Factory OCI is 3750 severe or 7500 normal service with conventional. 10k should be doable with a decent syn oil like QSUD, PP, PU, or the like. A UOA would tell for sure.

I typically do 5k conventional and 10k synthetic runs, as it keeps service easy for me to remember. Over the past 131k miles my Outback has seen conventional, blend, and synthetic...running whatever was on sale. Consumption remains at about half a quart over 5-6k miles, which is perfectally acceptable to me.

FWIW, my car seems to run smoother on PYB than anything right now, although I have not run the reformulated QSUD.
 
Most conventionals these days (dare I say all?) contain a decent amount of synthetic oil anyways. The newer API requirements are getting stricter which necessitates some synthetic content.
 
Well, sounds like I will be going conventional on the next change. I am a reformed synth junkie going on 4 years now, but the other stuff I have heard made me wonder about switching. Truth be told, i felt silly even asking, but wanted to cover all my bases. Thanks guys! I'll probably look at Castrol or Valvoline or even Supertech...whatever is cost effective.
 
Next silly question would be how many people here are using high mileage oils? I see them a lot but have zero experience with them. Another gimmick?
 
Originally Posted By: cowhorse01
Next silly question would be how many people here are using high mileage oils? I see them a lot but have zero experience with them. Another gimmick?


Nope. Not a gimmick. They can help leaking gaskets,excessive oil consumption etc.
 
Subaru is particularly lax in its recommendations/requirements regarding oil for these engines.

If you consult the manual, you'll note that it specifies an SJ or SH (or even SG) oil with a "preferred" viscosity of 5W-30 up to approximately 105 degrees F ambient temperature. I strongly assume this "preference" is primarily related to fuel economy concerns, and the manual goes on to recommend 10W-30 or 10W-40 for any ambient temperatures above approximately -5 degrees F.

To make things even more interesting, there is also a statement that, "If the vehicle is used in desert areas, in areas with very high temperatures, or used for heavy-duty applications such as a towing a trailer, use of oil with the following grade and viscosities is recommended: SJ or SH 30, 40, 10W-50, 20W-40, 20W-50." Yes, that's a straight 30 or 40 weight oil included in the recommendations.

It's interesting that you posted this in the HDEO forum, because HDEO is what I use exclusively in my 2006 Saab 9-2x (rebadged WRX) and my fiancee's 2001 Forester.

We live in northern NJ, and while it's certainly not a "desert area", it's relatively mountainous and we do a fair bit of stop-and-go driving as well as ascending and descending the aforementioned mountain grades on our daily commutes - enough so for me to personally consider ours "heavy-duty applications." In the summer, I use conventional 15W-40 HDEO (Rotella T this season) and switch to a 5W-40 such as Rotella T6 or DELO 400 LE in the winter. Since we put a decent amount of miles on our cars, I'll probably do an "autumn" change with Rotella T5 10W-30 as well before we actually hit the cold months.

My primary point in this lengthy anecdote is that A.) these Subaru engines are not at all particular about what oil they use (although I feel that they prefer something more viscous than the "recommended" 5W-30), and B.) There is no harm whatsoever in switching from synthetic to conventional or anywhere in between.
 
Hey By!

Why not add to the knowledge base??? Run any choice of syn, do a UOA at 5k miles without dumping it, and then UOA again at 10k. Then, do the exact same thing with a dino. Then you will KNOW what is best for your situation, rather than guessing!

I strongly suspect you'll find that dinos are up to the challenge. Obviously, the length of the intended OCI will play into this in a big way. But most dinos are WAY more capable than what folks give them credit for.

The NA 2.5L engine seems much easier on lube than what I've seen from the turbo version, overall.

I would think either a 5w-30 or 10w-30 would do fine in your area.
 
Originally Posted By: Clevy
Originally Posted By: cowhorse01
Next silly question would be how many people here are using high mileage oils? I see them a lot but have zero experience with them. Another gimmick?


Nope. Not a gimmick. They can help leaking gaskets,excessive oil consumption etc.


Exactly. We use maxlife HM around here in older trucks and it is an amazing product.

Dinos have improved so much that they are generally better than most folks need at the ridiculously short intervals some use. The only reason to use a synth anymore is "feel good" or for extended drains.
 
Originally Posted By: Padawan
Subaru is particularly lax in its recommendations/requirements regarding oil for these engines.

If you consult the manual, you'll note that it specifies an SJ or SH (or even SG) oil with a "preferred" viscosity of 5W-30 up to approximately 105 degrees F ambient temperature. I strongly assume this "preference" is primarily related to fuel economy concerns, and the manual goes on to recommend 10W-30 or 10W-40 for any ambient temperatures above approximately -5 degrees F.

To make things even more interesting, there is also a statement that, "If the vehicle is used in desert areas, in areas with very high temperatures, or used for heavy-duty applications such as a towing a trailer, use of oil with the following grade and viscosities is recommended: SJ or SH 30, 40, 10W-50, 20W-40, 20W-50." Yes, that's a straight 30 or 40 weight oil included in the recommendations.

It's interesting that you posted this in the HDEO forum, because HDEO is what I use exclusively in my 2006 Saab 9-2x (rebadged WRX) and my fiancee's 2001 Forester.

We live in northern NJ, and while it's certainly not a "desert area", it's relatively mountainous and we do a fair bit of stop-and-go driving as well as ascending and descending the aforementioned mountain grades on our daily commutes - enough so for me to personally consider ours "heavy-duty applications." In the summer, I use conventional 15W-40 HDEO (Rotella T this season) and switch to a 5W-40 such as Rotella T6 or DELO 400 LE in the winter. Since we put a decent amount of miles on our cars, I'll probably do an "autumn" change with Rotella T5 10W-30 as well before we actually hit the cold months.

My primary point in this lengthy anecdote is that A.) these Subaru engines are not at all particular about what oil they use (although I feel that they prefer something more viscous than the "recommended" 5W-30), and B.) There is no harm whatsoever in switching from synthetic to conventional or anywhere in between.


Thanks for the comprehensive info from a real world user. I believe I am leaning towards a conventional switchover, but not sure yet which one. Rotella or Delo sounds like a great idea since I use Delo in my truck. I might as well just keep to one oil and call it good, right? I am really glad to hear that the engines are easy on oil. I have also seen, from crawling around underneath, that these are extremely easy to work on. Even more of a bonus since I do most of my own stuff!
 
Originally Posted By: dnewton3
Hey By!

Why not add to the knowledge base??? Run any choice of syn, do a UOA at 5k miles without dumping it, and then UOA again at 10k. Then, do the exact same thing with a dino. Then you will KNOW what is best for your situation, rather than guessing!

I strongly suspect you'll find that dinos are up to the challenge. Obviously, the length of the intended OCI will play into this in a big way. But most dinos are WAY more capable than what folks give them credit for.

The NA 2.5L engine seems much easier on lube than what I've seen from the turbo version, overall.

I would think either a 5w-30 or 10w-30 would do fine in your area.



Yo Dave, I would gladly do a UOA other than lack of time/cost to really keep up with it. I am leaning towards just using the same oil I use in my truck and keeping it simple. It's been getting hotter here in Southern CA and the Delo for desert trips would do the Subie well I would think. Seems to be a really good oil. I have heard the heavier weight does them well against lifter ticking, but this car makes no noises like that yet. Needless to say, it seems like a great little wagon.
 
Originally Posted By: SteveSRT8
Originally Posted By: Clevy
Originally Posted By: cowhorse01
Next silly question would be how many people here are using high mileage oils? I see them a lot but have zero experience with them. Another gimmick?


Nope. Not a gimmick. They can help leaking gaskets,excessive oil consumption etc.


Exactly. We use maxlife HM around here in older trucks and it is an amazing product.

Dinos have improved so much that they are generally better than most folks need at the ridiculously short intervals some use. The only reason to use a synth anymore is "feel good" or for extended drains.


I completely agree on the synthetic issue. I am contemplating using the Maxlife, but will probably just go with the Delo on this first change. it keeps it simple for me with 2 vehicles. i like simplicity as I get older.
 
Originally Posted By: cowhorse01
Originally Posted By: SteveSRT8
Originally Posted By: Clevy
Originally Posted By: cowhorse01
Next silly question would be how many people here are using high mileage oils? I see them a lot but have zero experience with them. Another gimmick?


Nope. Not a gimmick. They can help leaking gaskets,excessive oil consumption etc.


Exactly. We use maxlife HM around here in older trucks and it is an amazing product.

Dinos have improved so much that they are generally better than most folks need at the ridiculously short intervals some use. The only reason to use a synth anymore is "feel good" or for extended drains.


I completely agree on the synthetic issue. I am contemplating using the Maxlife, but will probably just go with the Delo on this first change. it keeps it simple for me with 2 vehicles. i like simplicity as I get older.


Me, too! Nothing wrong with Delo, that's a great oil...
 
I like delvac and pennzoil long life. Had a large stash of bulk oil of rotella t i used for a couple years was a great oil to. If paying retail for 15w40 i go for the pennz. I have katz magnetic heaters and tank-style heaters on everything. So i stay with sae30 year around in the 97 7.3l powerstroke. My uncle has a trucking company, over 40 years millions of road and off road mile. Cummins power ford 9000's and IH trucks. Always sae30 yeararound. Never a oil related engine failure. Truck will be long gone over the hill and that engine will still pick another truck and spit it out. Keep good kleen good brand and quality oil in it and it will run a good long time.

Ken
 
Well guys, I am not one to say "oh this oil made such a difference in my car" etc...

In my day of going through the new addition to our car family, I decided to go with Delo 15w-40 just to keep it simple, along with a Fram XG synthetic filter for the first oil change. Let me just say that it was a fairly big difference just in engine noise reduction. Upon cold start-up, the normal ticks and rattles that were there were GONE!! The car definitely seemed to run just a tad smoother and have better lubrication behavior. Not sure what that means, but take it for what it's worth. Once again, proving that synthetics aren't the end-all-be-all.

Now, my fuel economy may or may not go down a little bit, but to me this oil is an excellent choice for it's ease of availability, it's protection levels, and the attractive price! I do plan on doing a UOA after 5000 miles and running it to 7500 or 10k depending on what the UOA tells me. Thanks for the input guys! Love this place!

Oil change cost: $11.57 for Delo 15w-40 and 8.97 for filter. Not too bad. I went ahead and spent that much on the filter with plans to run it out as far as I can.
 
Originally Posted By: JR
I like delvac and pennzoil long life. Had a large stash of bulk oil of rotella t i used for a couple years was a great oil to. If paying retail for 15w40 i go for the pennz. I have katz magnetic heaters and tank-style heaters on everything. So i stay with sae30 year around in the 97 7.3l powerstroke. My uncle has a trucking company, over 40 years millions of road and off road mile. Cummins power ford 9000's and IH trucks. Always sae30 yeararound. Never a oil related engine failure. Truck will be long gone over the hill and that engine will still pick another truck and spit it out. Keep good kleen good brand and quality oil in it and it will run a good long time.

Ken


Meant to tell you thanks for the input! I agree as well!
 
Great question, cowhorse01! This is one of the most persistent myths about switching oils types. You can switch from synthetic motor oil to conventional motor oil at any time . There will be no seal problems nor internal engine surface issues. – The Pennzoil Team
 
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