Hello everyone! Here's a UOA of our 2014 Forester XT.
Oil used on this sample was 5 qts. of Mobil 1 0W-40 and 1 qt. of Formula Shell Full Synthetic 5W-30. Sump capacity is 6 qts. with oil filter change. OCI of 5,193 miles was from Nov. 11, 2017 at 72,668 miles to Mar. 26, 2018 at 77,861 miles. Mileage of vehicle when oil sample was taken is 77,861 miles.
I also replaced the engine air filter about midway through this OCI. Filter was replaced at 75,921.
OEM air filter was in use from Nov. 3, 2015 at 30,009 miles to January 28, 2018 at 75,921 miles. Filter had 45,912 miles at the time of replacement. New filter installed is an AEM Dry Flow filter.
Reason for not following Subarus's air filter replacement interval of 30K miles you ask? I've been around BITOG for a while now and read many posts regarding air filters becoming more efficient at filtering finer contaminants when used longer so I decided to install a filter restriction gauge and decided that I would replace the filter once I got to 15" of H2O vacuum on the Filter Minder (Self made up number to go by).
I then got to thinking what if by having a slightly more restrictive air filter all in the name of filtering efficiency, I could now be sacrificing turbo longevity since the turbo is now having to work harder (by how much I do not know) to compensate for the more restrictive filter so that the engine is hitting the target HP/Torque commanded by the ECU. This made me replace the filter sooner than I planned.
I had 2 reasons for having the UOA done.
1st/main reason for the UOA
At 60K miles, I installed 2 oil catch cans. 1 on the PCV side and another on the CCV (Turbo) side.
It has always bugged me whether the hose connections where properly sealed since the installation was somewhat custom. I sourced most of the hose used in the install. I wanted to see if I have been having dirt ingestion issues, plus the possible dirt ingestion from replacing the air filter midway through the OCI.
2nd reason for the UOA
This OCI consisted of many extremely short trips with a decent amount of 35 miles plus one way trip. I live in the DC Metro area to give you an idea of our winter conditions.
Driving pattern for the duration this OCI are as follows:
Monday - Oneway trip of about 35 miles into DC. Sits for 8 hrs. then started back up for a 2 mile trip within the city and then shut off.
Tuesday - 2 mile trip in the morning then shut off. Sits for 8 hrs. then started back up for a 2 mile trip within the city then shut off.
Wednesday to Thursday - Same as on Tuesday drive cycle.
Friday - 2 mile trip in the morning then shut off. After office hrs. on a Friday can either be another 2 mile trip then shut off then leave the vehicle for the weekend in DC or I tell my wife to take the vehicle home which then is 35 miles away.
During the above drive cycle, the oil temp. only gets to 150F to 175F.
There are weekends where we use it to travel to friends and families which are far enough to get the oil to full operating temperature which is around 194F to 210F.
Sorry for the long winded post but I wanted to give everyone a snap shot into the history of this UOA so that if there are figures that look amiss, people would be able to make sense of it. Everything looks good to me though! Let me know what ya'll think.
Oil used on this sample was 5 qts. of Mobil 1 0W-40 and 1 qt. of Formula Shell Full Synthetic 5W-30. Sump capacity is 6 qts. with oil filter change. OCI of 5,193 miles was from Nov. 11, 2017 at 72,668 miles to Mar. 26, 2018 at 77,861 miles. Mileage of vehicle when oil sample was taken is 77,861 miles.
I also replaced the engine air filter about midway through this OCI. Filter was replaced at 75,921.
OEM air filter was in use from Nov. 3, 2015 at 30,009 miles to January 28, 2018 at 75,921 miles. Filter had 45,912 miles at the time of replacement. New filter installed is an AEM Dry Flow filter.
Reason for not following Subarus's air filter replacement interval of 30K miles you ask? I've been around BITOG for a while now and read many posts regarding air filters becoming more efficient at filtering finer contaminants when used longer so I decided to install a filter restriction gauge and decided that I would replace the filter once I got to 15" of H2O vacuum on the Filter Minder (Self made up number to go by).
I then got to thinking what if by having a slightly more restrictive air filter all in the name of filtering efficiency, I could now be sacrificing turbo longevity since the turbo is now having to work harder (by how much I do not know) to compensate for the more restrictive filter so that the engine is hitting the target HP/Torque commanded by the ECU. This made me replace the filter sooner than I planned.
I had 2 reasons for having the UOA done.
1st/main reason for the UOA
At 60K miles, I installed 2 oil catch cans. 1 on the PCV side and another on the CCV (Turbo) side.
It has always bugged me whether the hose connections where properly sealed since the installation was somewhat custom. I sourced most of the hose used in the install. I wanted to see if I have been having dirt ingestion issues, plus the possible dirt ingestion from replacing the air filter midway through the OCI.
2nd reason for the UOA
This OCI consisted of many extremely short trips with a decent amount of 35 miles plus one way trip. I live in the DC Metro area to give you an idea of our winter conditions.
Driving pattern for the duration this OCI are as follows:
Monday - Oneway trip of about 35 miles into DC. Sits for 8 hrs. then started back up for a 2 mile trip within the city and then shut off.
Tuesday - 2 mile trip in the morning then shut off. Sits for 8 hrs. then started back up for a 2 mile trip within the city then shut off.
Wednesday to Thursday - Same as on Tuesday drive cycle.
Friday - 2 mile trip in the morning then shut off. After office hrs. on a Friday can either be another 2 mile trip then shut off then leave the vehicle for the weekend in DC or I tell my wife to take the vehicle home which then is 35 miles away.
During the above drive cycle, the oil temp. only gets to 150F to 175F.
There are weekends where we use it to travel to friends and families which are far enough to get the oil to full operating temperature which is around 194F to 210F.
Sorry for the long winded post but I wanted to give everyone a snap shot into the history of this UOA so that if there are figures that look amiss, people would be able to make sense of it. Everything looks good to me though! Let me know what ya'll think.