The 2015 Subaru Forester is speced at using a 5W30 synthetic oil.Would it be a warrenty issue if a 5W40 synthetic was used?For warrenty I would rum a 6K OCI.Thanks Joe
2015 Subaru 2.0 turbo
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Joe,
not sure why you want to run a 40, but it might draw the crabs if you hand them a jug of 5W40 come service time and ask them to install it.
You could pick an A3 5W30, and not have any potential issues, as unlikely as the 40 case are.
not sure why you want to run a 40, but it might draw the crabs if you hand them a jug of 5W40 come service time and ask them to install it.
You could pick an A3 5W30, and not have any potential issues, as unlikely as the 40 case are.
It's not up to us or you if it'll be a warranty issue. It'll be up to Subaru. If you're in need of a major repair that can be blamed on your oil choice, it'll give them an easy out.
Unless there's an exception to the 5W-30 requirement in your owners manual, stick with that through the warranty period. There are some good UOAs around here with Pennzoil Ultra 5w-30 in that motor, for whatever it's worth.
Unless there's an exception to the 5W-30 requirement in your owners manual, stick with that through the warranty period. There are some good UOAs around here with Pennzoil Ultra 5w-30 in that motor, for whatever it's worth.
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+1 on the German Castrol 0W30, very well liked by Subaru turbo owners. Stay away from Mobil 1, for some reason most Soob folks report badly on it.
Stick with what your owner's manual says until the warranty is up. If you are wanting 5w40 because it is a HDEO, the look around as there are HDEO that are in the 5w30 flavor. Just make sure it meets SN spec.
This subject is always debated since SoA dropped 5W-40 from most of the temp charts since 2011. However, 5W-40 is on the temp chart in the 2015 WRX manual, although the language only states to use 5W-30 synthetic "for optimum engine performance" (like your manual does); "5W-40 conventional"
can be used for relplenishment only (like your manual states); and "thicker viscosity is required in higher temps (ditto, and higher temps are not defined)".
Yes, warranty will be up to your dealer and SoA but you might want to have a look at the few DIT Forester uoa's posted in the uoa forum here as well as the DIT forum at subaruforester.org (in the uoa sticky). Both the '15 WRX and '14/'15 FXT are seeing some very high fuel dilution (3-6% tested by Blackstone) and some viscosities coming back barely as a 20 grade.
If you decide to run a GF5 5W-30 oil I would cut the OCI back to 3k miles and make sure you keep all of your oil receipts. GC is great oil, but it's API SL. And Mobil1 is an excellent choice. Regular M1 5W-30 gets a bad rap because it's popular and it shears out of grade in a Subie turbo. Just like most every GF5 5W-30.
Yes, warranty will be up to your dealer and SoA but you might want to have a look at the few DIT Forester uoa's posted in the uoa forum here as well as the DIT forum at subaruforester.org (in the uoa sticky). Both the '15 WRX and '14/'15 FXT are seeing some very high fuel dilution (3-6% tested by Blackstone) and some viscosities coming back barely as a 20 grade.
If you decide to run a GF5 5W-30 oil I would cut the OCI back to 3k miles and make sure you keep all of your oil receipts. GC is great oil, but it's API SL. And Mobil1 is an excellent choice. Regular M1 5W-30 gets a bad rap because it's popular and it shears out of grade in a Subie turbo. Just like most every GF5 5W-30.
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An alternative is to do something like go with a HM oil even though it's a new engine. Using a HM oil will not cause any harm, and some HM are on the thicker side. Pennzoil HM and Havoline HM are both on the thicker side to the point of getting near a 40 weight.
Originally Posted By: bluesubie
This subject is always debated since SoA dropped 5W-40 from most of the temp charts since 2011. However, 5W-40 is on the temp chart in the 2015 WRX manual, although the language only states to use 5W-30 synthetic "for optimum engine performance" (like your manual does); "5W-40 conventional"
can be used for relplenishment only (like your manual states); and "thicker viscosity is required in higher temps (ditto, and higher temps are not defined)".
Yes, warranty will be up to your dealer and SoA but you might want to have a look at the few DIT Forester uoa's posted in the uoa forum here as well as the DIT forum at subaruforester.org (in the uoa sticky). Both the '15 WRX and '14/'15 FXT are seeing some very high fuel dilution (3-6% tested by Blackstone) and some viscosities coming back barely as a 20 grade.
If you decide to run a GF5 5W-30 oil I would cut the OCI back to 3k miles and make sure you keep all of your oil receipts. GC is great oil, but it's API SL. And Mobil1 is an excellent choice. Regular M1 5W-30 gets a bad rap because it's popular and it shears out of grade in a Subie turbo. Just like most every GF5 5W-30.
That language allows for a thicker oil. With the fuel dilution I would run a 40 weight without hesitation. M1 0w40 & RT6 would be on my short list.
This subject is always debated since SoA dropped 5W-40 from most of the temp charts since 2011. However, 5W-40 is on the temp chart in the 2015 WRX manual, although the language only states to use 5W-30 synthetic "for optimum engine performance" (like your manual does); "5W-40 conventional"
Yes, warranty will be up to your dealer and SoA but you might want to have a look at the few DIT Forester uoa's posted in the uoa forum here as well as the DIT forum at subaruforester.org (in the uoa sticky). Both the '15 WRX and '14/'15 FXT are seeing some very high fuel dilution (3-6% tested by Blackstone) and some viscosities coming back barely as a 20 grade.
If you decide to run a GF5 5W-30 oil I would cut the OCI back to 3k miles and make sure you keep all of your oil receipts. GC is great oil, but it's API SL. And Mobil1 is an excellent choice. Regular M1 5W-30 gets a bad rap because it's popular and it shears out of grade in a Subie turbo. Just like most every GF5 5W-30.
That language allows for a thicker oil. With the fuel dilution I would run a 40 weight without hesitation. M1 0w40 & RT6 would be on my short list.
wemay
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Originally Posted By: LoneRanger
+1 on the German Castrol 0W30, very well liked by Subaru turbo owners. Stay away from Mobil 1, for some reason most Soob folks report badly on it.
It's not that Mobil 1 is bad... it 's that most passenger 5w30's ( including "regular...M1 5w30 ) fall under the Resource Conserving umbrella... and most seem to shear out of grade very quickly in a turbo motor, now with an oil chopping timing chain as well... add fuel dilution to the mix, and the oil can get VERY thin...
M1 0w40 , or M1 5w30 ESP, or M1 5w40 TDT are all solid oils... as is the regular 5w30, in the right application.
+1 on the German Castrol 0W30, very well liked by Subaru turbo owners. Stay away from Mobil 1, for some reason most Soob folks report badly on it.
It's not that Mobil 1 is bad... it 's that most passenger 5w30's ( including "regular...M1 5w30 ) fall under the Resource Conserving umbrella... and most seem to shear out of grade very quickly in a turbo motor, now with an oil chopping timing chain as well... add fuel dilution to the mix, and the oil can get VERY thin...
M1 0w40 , or M1 5w30 ESP, or M1 5w40 TDT are all solid oils... as is the regular 5w30, in the right application.
wemay
Site Donor 2023
Originally Posted By: geeman789
Originally Posted By: LoneRanger
+1 on the German Castrol 0W30, very well liked by Subaru turbo owners. Stay away from Mobil 1, for some reason most Soob folks report badly on it.
It's not that Mobil 1 is bad... it 's that most passenger 5w30's ( including "regular...M1 5w30 ) fall under the Resource Conserving umbrella... and most seem to shear out of grade very quickly in a turbo motor, now with an oil chopping timing chain as well... add fuel dilution to the mix, and the oil can get VERY thin...
M1 0w40 , or M1 5w30 ESP, or M1 5w40 TDT are all solid oils... as is the regular 5w30, in the right application.
Although with you where modified, track day frequented subies are concerned, I believe most WRX/STi (left in stock form daily driver) owners use a resource conserving synthetic like M1 etc., if for nothing else but name recognition associated with a quality product. Most have never heard of us crazies on BITOG or care to read forum banter... and will be just fine for it.
Originally Posted By: LoneRanger
+1 on the German Castrol 0W30, very well liked by Subaru turbo owners. Stay away from Mobil 1, for some reason most Soob folks report badly on it.
It's not that Mobil 1 is bad... it 's that most passenger 5w30's ( including "regular...M1 5w30 ) fall under the Resource Conserving umbrella... and most seem to shear out of grade very quickly in a turbo motor, now with an oil chopping timing chain as well... add fuel dilution to the mix, and the oil can get VERY thin...
M1 0w40 , or M1 5w30 ESP, or M1 5w40 TDT are all solid oils... as is the regular 5w30, in the right application.
Although with you where modified, track day frequented subies are concerned, I believe most WRX/STi (left in stock form daily driver) owners use a resource conserving synthetic like M1 etc., if for nothing else but name recognition associated with a quality product. Most have never heard of us crazies on BITOG or care to read forum banter... and will be just fine for it.
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Originally Posted By: wemay
Although with you where modified, track day frequented subies are concerned, I believe most WRX/STi (left in stock form daily driver) owners use a resource conserving synthetic like M1 etc., if for nothing else but name recognition associated with a quality product. Most have never heard of us crazies on BITOG or care to read forum banter... and will be just fine for it.
The previous generations of WRX engines (same engine in current WRX STI...) had a reputation for being susceptible to scuffed or spun bearings. Many on stock cars.. So, some owners use a thicker oil, thinking that it may prevent a bearing issue...
However, the root cause of these failures is debatable. Low oil levels, too thin oil viscosity, poor factory fuel maps causing detonation, poor overall lubrication design... who knows.
Although with you where modified, track day frequented subies are concerned, I believe most WRX/STi (left in stock form daily driver) owners use a resource conserving synthetic like M1 etc., if for nothing else but name recognition associated with a quality product. Most have never heard of us crazies on BITOG or care to read forum banter... and will be just fine for it.
The previous generations of WRX engines (same engine in current WRX STI...) had a reputation for being susceptible to scuffed or spun bearings. Many on stock cars.. So, some owners use a thicker oil, thinking that it may prevent a bearing issue...
However, the root cause of these failures is debatable. Low oil levels, too thin oil viscosity, poor factory fuel maps causing detonation, poor overall lubrication design... who knows.
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