Forester XT 14+ FA20DIT Subaru 5w-30??? 2500Mi

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Hi guys, This is my first post so apologies if there are errors.

After my first oil change by Subaru I suspected that the oil used was not as specified by the manual which states use 5w-30 but NEVER to use 0w-20 which I suspected they used. My analysis was done by ALS Tribology here in Australia. The report states that viscosity was low due to fuel dilution. I suspect it was low because they used 0w20. Here are the results...

COMPONENT Kms 16900
MACHINE Kms 16900
OIL Kms 4400
OIL MAKE Unidentified
OIL TYPE SAE
OIL GRADE SAE 5W30???


Physical Tests

Water (%) span>
Viscosity (cSt,100°C) 8.3
Fuel (% by G.C.) 1.2
Dispersancy Pass
Oxidation (Abs) 13.5
Nitration (Abs) 8.4
Total Base Number (FTIR) 8.3

Now my questions to you all is:

1) Would a 1.2% fuel dilution cause a shearing of viscosity to 8.3 if 5w30 oil had originally been used? (My basic understanding is that if that oil had been used minimum value should be 9.3 and max 12.49 @100deg C.)

2) Is a 1.2% fuel dilution after 4400kms (2500Mi) and acceptable value for a direct injection, turbo, high compression engine (10.6:1) such as the FA20DIT?

3) Are these totally acceptable values, the correct oil was used and I am overreacting?

Any input appreciated. If you require anymore information please let me know and I will provide it to you.

Thanks all.
 
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Fuel dilution is acceptable if you made a lot of short trips, but could be an issue if you drove a lot of hwy mileage.

The 8.3 Vis is very suspect if you weren't redlining the engine every day because a full synthetic 5w30 (Subaru manuals state that all turbo engines req full synth) will never shear that fast under normal conditions. Given that most 0w20 oils start with a Vis of ~8.5, it does look likely that it was put in your car.

What made you suspicious in the first place? Did the report include any wear metal data?
 
Thank you both for your responses.

HK, what made me suspicious was that the engine was making more noise than usual after I picked it up for service. When I checked my receipt it stated that 0w20 had been used. When I approached the service guy he said that the engine only used 5w30 and there is no way that they would have used 0w20 and it was an administration mistake.

Greasymechtech, The thing is I cant keep getting the oil analyzed here in Australia as that test was pretty expensive at $70Au or $65us per examination. Another thing is that the service interval for the vehicle is 12500kms or 7767Miles, If I had of let that oil go till next service it almost certainly would have been too degraded by fuel contamination to do its job. Wouldnt you agree?

I do have the metal wear data for you guys. It all appears acceptable, but I feel if I had left that oil in the engine any longer it would have caused damage so I did an oil and filter change to the correct oil 5w30 GF-5. Here is the wear:

Metals (ppm)
Iron (Fe) 18
Chromium (Cr) span>
Lead (Pb) 2
Copper (Cu) 20
Tin (Sn) span>
Nickel (Ni) span>
Aluminium (Al) 7
Titanium (Ti) 4
Silver (Ag) span>

Contaminants and Additives (ppm)
Silicon (Si) 64
Sodium (Na) 2
Potassium (K) span>
Boron (B) 21
Calcium (Ca) 2208
Zinc (Zn) 871
Phosphorus (P) 709
Magnesium (Mg) 12
Molybdenum (Mo) 67
Cadmium (Cd) span>
Sulphur (S) span>

Thank you again for your input. I really appreciate your help.
smile.gif
 
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We'll see in the future if more owners with this engine have similar UOAs.

With your climate, I wouldn't fear going a little thicker with the oil until more info is known. And, I would also keep a conservative
Good luck and enjoy the vehicle.
 
Thanks mate. Just to be safe ill be sticking to 6000km changes which is twice as often as prescribed by Subaru. Now if only I can get the dealer to put the correct oil in to start with. Im very angry about that.

Definitely an enjoyable car to drive.
smile.gif
 
Originally Posted By: HKPolice
Fuel dilution is acceptable if you made a lot of short trips, but could be an issue if you drove a lot of hwy mileage.

The 8.3 Vis is very suspect if you weren't redlining the engine every day because a full synthetic 5w30 (Subaru manuals state that all turbo engines req full synth) will never shear that fast under normal conditions. Given that most 0w20 oils start with a Vis of ~8.5, it does look likely that it was put in your car.

What made you suspicious in the first place? Did the report include any wear metal data?

These cars indeed can shear Resource Conserving GF5 5W-30's down to a 20 grade in 2,500 miles or less, with or wiithout fuel dilution. If the OP's 5W-30 oil meets ACEA A3, then it's more likely that the oil would have stayed a 30 grade.

http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3442654

-Dennis
 
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It reads like a low quality 30 grade ILSAC oil with moderate fuel dilution (~3oz). I think your KV would be in the high 7's if you used Idemitsu 20 grade and had 1.5% fuel. Engine just went through the nastiest part of break-in, so shear and fuel dilution are expected to be high.
 
Some great info to research here guys. Thank you all for taking the time to look at my results and reply.

I will post up my next results with a known oil and compare.
 
Thought I'd add to this thread rather than starting my own. I've got a MY13 XT Forester with the FA20DIT and have had it dealer serviced since new.

Last service they billed it out with 0W20 instead of the usual 5W30 they recommend for Australia. Turns out it was done in error by a loan mechanic who normal does other makes. They changed it for me the next day but after about 6000km the engine had a lot of light tapping noises at idle when the oil was hot.

Thinking they'd just left the 0W20 in I changed the oil to this Penrite 5W30. Tapping noise disappeared completely and I sent the oil off for analysis. It came back with a viscosity (cSt,40°C) of 59 and everything else within normal wear ranges. Unfortunately they didn't do a fuel level as part of the test. However it looks like the oil was the Castrol Edge A3 5W30 that was meant to be in there but it had gone from 70 (cSt,40°C) down to 59. I assume this was partially due to fuel dilution.

With the car out of warranty next month and me planning to do my own oil changes I'm thinking of using this new Penrite 5W30. It's thicker than a true GF5 5W30 oil as recommended by Subaru but looks to better suit this motor to limit the effects of fuel dilution and valve deposits.
 
Originally Posted By: mickjf

With the car out of warranty next month and me planning to do my own oil changes I'm thinking of using this new Penrite 5W30. It's thicker than a true GF5 5W30 oil as recommended by Subaru but looks to better suit this motor to limit the effects of fuel dilution and valve deposits.

Some WRX and DIT Forester owner's in the U.S. are using ACEA C3 oils for this reason as well. Although, Subaru Japan still allows high SAPS 0W-30 and 5W-40 in DIT engines.

http://www.subaru.jp/accessory/engine_oil/engine_oil/

(I believe the Castrol SLX Pro is high SAPS).

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