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synthetic oil recommended change interval and oil filters

13K views 15 replies 11 participants last post by  neoshi  
#1 ·
So I decided to try and change my own oil on my 'new' (for me) 2003 Forester. This is will be my first attempt to do an oil change. After a lot of reading about oils, I decided on go for Pennzoil Platinum this time (got 5Q's in Wal-mart for $20) and may try AMSoil for the next change. Living in Colorado, I believe I will benefit from it especially in the upcoming winter months. So now, I have a few questions:

1. What is the recommended oil change interval for Pennzoil Platinum? Their label say to check out the owners manual but 03's manual does not have guides for synthetics other than stating to follow the same oil change guidelines. Obviously synthetic oil does not break down as dyno so I think I can go at least 10000 miles? Just want to get your thoughts. I know Mobil one does state on their label that their synthetic is 15,000 miles or 1 year.

2. Do synthetic oils need special oil filters or the regular ones should be fine? I got a NAPA ProSelct Filter (#21365) when I got a new crash washer there for the oil drain plug (20m). Are 'brand' filters any better/recommended?

3. Sometimes people say that you can keep using the synthetic oil for longer periods but change the filter every 3000 miles anyway. Is this true? If so, would changing the filer result in a leak while taking the old one off and putting a new one one?
 
#2 ·
The interval and what filter to use is highly debateable, but I would not recommend exceeding 5k between changes on the principle basis that all oils get dirty.
 
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#3 ·
There is not a great difference between syn oils and dino oils today.

Without an oil analysis (Blackstone Labs) you really don't want to go much over say 6K on any oil.

Same filters.

RedLine, Motul, Amsoil, Royal Purple, Amsoil are Group IV Syns. The rest are Group III (cheaper varieties..really not "true syns) Penzoil Plat included.

There are ton's of posts on this subject.
 
#4 ·
Opinions

So I decided to try and change my own oil on my 'new' (for me) 2003 Forester. This is will be my first attempt to do an oil change. After a lot of reading about oils, I decided on go for Pennzoil Platinum this time (got 5Q's in Wal-mart for $20) and may try AMSoil for the next change. Living in Colorado, I believe I will benefit from it especially in the upcoming winter months. So now, I have a few questions:

1. What is the recommended oil change interval for Pennzoil Platinum? Their label say to check out the owners manual but 03's manual does not have guides for synthetics other than stating to follow the same oil change guidelines. Obviously synthetic oil does not break down as dyno so I think I can go at least 10000 miles? Just want to get your thoughts. I know Mobil one does state on their label that their synthetic is 15,000 miles or 1 year.
>>Personally keeping oil in your oil pan for one year...wow I do not think that to be prudent. Most Garage's recommend 3 months or 5000 KM in Canada ( climate has some say in this ) but also the owners manual recommends changing your oil every 5000 KM regardless of Syn vs conventional.

2. Do synthetic oils need special oil filters or the regular ones should be fine? I got a NAPA ProSelct Filter (#21365) when I got a new crash washer there for the oil drain plug (20m). Are 'brand' filters any better/recommended?
>>People on the forum really like the Subaru filter, avoid the cheap filters.

3. Sometimes people say that you can keep using the synthetic oil for longer periods but change the filter every 3000 miles anyway. Is this true? If so, would changing the filer result in a leak while taking the old one off and putting a new one one?
>>You will get a little messy when spinning your filter, make sure to have a rag with you :)

>> I recently switched to Synthetic myself, and I keep the same interval as I did with conventional oil, it cost me roughly $ 20.00 more per oil change, but for my peace of mind I feel it is worth it. I was going to spin/replace the filter, but the particles in the oil that the filter catches are not the only contaminants. I switched to syn oil for better protection. I will use an analogy that some may find crude.

Would anyone re-use a prophylactic ?

And I do not want an answer to that analogy :)

Cold weather starts nobody disputes that Syn oil is better, it is all about your comfort level.
 
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#5 ·
100% depends on your driving style and conditions.

6k is a good place to start.

For our Foz, we've gotten a couple Blackstone Used Oil Analysis done, and established that our change interval is 10,000. We drive 95% on the highway, so that's okay for us. If you drive in the city/suburban environments, or drive spiritedly, you'll want to change more often. Every car and driver has a different change interval, you just have to find one that fits you. :icon_wink:

As an example:
In my pickup, I use the same oil (Mobil 1 5W-30 Synthetic ) changed every 3500 miles, because it is a high performance engine doing a lot of work (towing/hauling). Same oil, same filter brand, different engine and driving conditions. The Forester drives almost always on long highway trips, and doesn't do that much 'hard' work.
 
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#12 ·
100% depends on your driving style and conditions.
QFT

Subaru recommends a 7500 mile interval for 2009 models. Are you saying that this is an error?
You can put 30,000 miles on the same oil if you drive 1000 miles every day for a month, and it will still have some life left in it. You can also start it up every morning and drive it across the street every day for 5 months and put < 100 miles on it, and you would be overdue for an oil change. There really are too many factors to determine an oil change interval based on miles alone.
 
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#6 ·
A syn should easily go twice as long as a dino. I'd sday you're safe at least 5k, if not more like 7 to 8 k on a syn. For a filter to go that long, use a good 'un. The Purolator PureOne has the bypass setting closest to Subie OEM and it's a top grade filter. I just bought a few of them yesterday because I'm changing the oil on my OBW today. Don't forget a new crush washer.

I've personally had good luck with M1, Pennz Plat and Valo Synpower.
 
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#7 ·
Thanks for the replies everyone! I really appreciate you input. Once I get past 4K miles I will watch it much more closely to see how is the condition/color and go from there. MIght have to send a 6K miles test for analysis to see the results and then go from there.

Thanks again!
 
#11 ·
Just for reference, in case someone is searching this thread in the future, here is how SOA defined severe driving conditions (for oil changes every 3750 miles instead of 7500):

a. Repeated short distance driving when the engine does not reach normal operating temperature.
b. Driving on rough and/or muddy roads.
c. Driving in dusty conditions.
D. Driving in extremely cold weather.
e. Driving in areas where road salts or other corrosive materials are used.
f. Living in coastal areas.
g. Towing a trailer.
 
#13 ·
Thanks for posting this, my driving doesn't fit this description. I figure if SOA and the dealer says 7500 is the interval, I'm OK with it. We change the oil in our 2007 Toyota Prius every 5,000 miles and it's got 23k on it now and not burning a drop. I have 7777 (yes, that is what it said tonight when I shut the car off) miles on my Subaru and the engine is as tight as a drum, not burning any oil here.
 
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#14 ·
On a first changeover to SOPUS PP synthetic (fauxsyn), I would not go over 5K due to cleanup this oil will do and the 3/4 litre old oil left in the engine; on your next oil change, should be no problem going 7500 miles between as long as you dont do a lot of short trips and use the same oil chemistry as before. BTW, Redline is a group V syn oil - REAL synthetic POE majority basestock (turbofan jet lube), good for extreme high temp applications. Most US sourced "synthetic' oils are (just) highly processed conventional oil with premium additives and higher detergent loads. they approach GTO and other synthesis methods in cold temp viscosity and boil off but are not in the same league as group V basestocks AT ALL. This does not in any way make them a BAD lubricant for 90% of the population, however.
 
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#16 · (Edited)
Ah the good ol' synthetic vs conventional debate. Just remember that synthetic oil use on mainstream passenger cars was a marketing job by Mobil 1 and they originally touted 20k between changes, but shortly retracted that claim. But the origin of synthetic oils was by AMSOIL for things like FIGHTER JETS because the oil would resist HIGH TEMPERATURE viscosity breakdown.

So I'd say if you track your car any or drive aggressively/fast all the time, go synthetic since you're really heating that oil. If you are a cruiser, conventional oil should work fine.

I'd still stick to the regular intervals, though even the intervals is another story all together (manufacturer liability claims, age of detergent-less motor oils (which we no longer have)).

/ninja

Oh I forgot about oil filters.. I don't know what to say really. The most preached claim is that the manufacturer's filter is still be the best. Now if Subaru stuck to Tokyo Roki's ("blacks"), I'm sure we would probably believe this. But with this new blue Honeywell/FRAM (and you know there is this anti-FRAM thing going on everywhere), nobody knows anymore. So there have been numerous threads about cutting open filters and analyzing them. Purolator PureONEs are still touted as the best aftermarket but this could just be the effect of group think. Same goes for WIX and a few other brands. Your best bet is the ADC METHOD. Stick to one oil brand (this will be your control), buy a filter, use it, test the oil through Blackstone Labs, and see which one fits your bill.
 
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