I have done very extensive research about the types of oil that are out there, the difference between synth and dino, the viscosity, climate considerations, thickness etc. I understand there are certain rules of using them as well it is up to the driver to use its own kind - the preferred one.
Here are the links I found on this forum (thank you they were very helpful):
I also need to admit, that this is my first post on this forum.... I will try my best to post more....but i guess this is a good beginning.
I understand that this topic was brought up many times, but I really could find the answers I was looking for the past 3 days. Most of the replies are rather general than specific, that why I need to ask for everyone's opinion.
I have a very general question about oil change and how it would affect the motor.
Recently I bought 2004 WRX with 39000, everything stock no mods no nothing. Right now I am up to 44500 miles, I was using regular oil, changed it every 1500-2000 at the local subaru dealership (I would never go to them again since with the last oil change they didn't refill it completely, when I checked it was lower than the E mark).
Recently I decided to switch to the M1 Synth oil 5W-30 with Mobil Extended Performance Oil Filter, supposedly it is one of the top quality brands for both (DUHHH). Before I switched Subaru Dealership used Agip dino 5W-30 oil.
I am wandering if I haven't switched to late. Some say it is to late some people don't I guess there is not general rule for that?
I guess there might be some drawbacks from switching back to dino oil, but obviously there are no negative reasons why to switch back?
To support my point we can go back to research done by Paradise Garage "Synthetic Oil Life Study" and their findings about M1 Synth 5W-30 oil:
Here is a complete research they have done:Looks like they've tweaked the formula a bit since last time: boron is about a fourth of its previous value, and phosphorus and zinc are down about 25%. Nothing seems to have risen appreciably, though, which means they're putting less "stuff" in their oil -- or they're using something we're not testing.
The owners manual states that you can use synth oil as long as it has the same GF-x category and is certified by API / SAE.
The oil engine cap on mine WRX says GF-3 but as mentioned by NASIOC specialist GF-4 is backward compatible to GF-3 but not vice-versa:
I am bringing it up since the oil I purchased at Strauss has been rated in GF-4 category, but according to whatever I have found I should be good with the oil I purchased?The categories are backwards-compatible with all previous categories, however they are not cross-compatible. For instance, GF-4 can be used in-lieu of GF-3, but GF-3 cannot be used when GF-4 is required.
In addition according to NASIOC forum, all Subarus can use synth as long as Owners Manual says so, I guess this can be debated for hours:
So all the facts I brought up show, but not necessarily prove that synthetic oil is the right oil to use?Clarifications:
1) Synthetic oil can be safely used provided the viscosity and oil grade classifications as noted in the Owners Manual are used. The oil change interval noted in the maintenance schedule must still be adhered to.
2) Severe Driving Conditions will require the oil change interval to be increased to 3,750 miles or 3.75 months. New for 2008: All turbocharged models are considered to be operated under severe driving conditions and require the oil interval of 3,750 miles or 3.75 months.
Just to add more on to the question, NASIC forum moderator stated the following:
So it seems that all of them are good choices although he is not encouraging to use synthetic oil?Summary:
* Use a GF4/SM oil if you have a 2006 or later Subaru
* change your oil at 3750 miles
* use synthetic if you want
List of GF-4 (or SM) approved oils:
Amsoil ASL High Performance 5w30
Amsoil XLF Extended Life 5w30
Castrol Syntec 5w30
Mobil1 Extended Performance 5w30
Pennzoil Platinum 5w30
Redline Synthetic 5w30
Valvoline SynPower 5w30
What is NOT GF-4 (or SM) approved?
He is also saying that "Use a GF4/SM oil if you have a 2006 or later Subaru" - so this means older versions shouldn't use GF-4 only GF-3 or later opposing to the fact that GF-4 is backwards COMPATIBLE to GF-3?
Also, I don't know if this is normal or not (since I never owned a Subaru before) when you start the engine an it warms up usually at 1.5k rpm, I can hear like a quiet knocking sound (can't really describe it). The sound is present only on low RPM usually up to 2k. Is this normal? The RPMs are stable, I haven't encouraged any issues while driving, but I am concerned about that sound. Any suggestions?
To add more I haven't noticed any oil consumption while driving. I raced the engined few times while driving upstate New York on highways, so far only that was done only on Dino.
I haven't have a change to to drive long runs on the M1, but I will post my results to keep the conversation open at least for a while.
Really, I am very sorry for the post to be so extensively long. I just wanted to make my point and ask the right questions. I would appreciate the help of forum members and their feedback on the topic of "Oil change, synth or dino, when to change?".
If anyone has a suggestion for me please let me know, any feedback is greatly appreciated.
Thank you ClubWRX Forum.