2017 WRX STI: Motul X-clean EFE - 5,000 miles

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Copper is probably from the oil cooler. Its been seen a lot on WRX engines. The other possible source is the crank bearings, yet it just seems unlikely here.
 
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What?
Originally Posted By: Gubkin
"TBN is still good at 2.2. Try 7000 miles" Crazy lab! ))))))) It's mean that TBN > TAN necessary decrease interval to 4000 miles
 
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Very good metal wear rates. Cu and (part of) Al likely comes from cooler, not bearing. This C3 oil of TBN 7.8 drops to 2.2 over 5100 miles, which I interprete as good TBN retention. I won't look at TAN , if any, and agree with BStone OCI could be extended further to 7000 miles or probably beyond. Edit:The test of the pudding is in the eating, which in this case refers to (the very good) Fe wear of 5 ppm over 5100 miles.
 
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I believe that Blackstone uses a different ASTM test than either of those (at least they used to). https://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=221275 I doubt the OP will extend the interval very much. And probably not likely to go beyond 6k miles which is Subaru of America's recommendation unless Blackstone will cover the Powertrain Warranty. smile2
 
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Originally Posted By: zeng
Very good metal wear rates. Cu and (part of) Al likely comes from cooler, not bearing. This C3 oil of TBN 7.8 drops to 2.2 over 5100 miles, which I interprete as good TBN retention. I won't look at TAN , if any, and agree with BStone OCI could be extended further to 7000 miles or probably beyond. Edit:The test of the pudding is in the eating, which in this case refers to (the very good) Fe wear of 5 ppm over 5100 miles.
Wear metals ppm is only a piece of the story. You will not see deposit formation in a UOA, which you get from low TBN or where TAN is higher than TBN.
 
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Originally Posted By: 1JZ_E46
Originally Posted By: zeng
Very good metal wear rates. Cu and (part of) Al likely comes from cooler, not bearing. This C3 oil of TBN 7.8 drops to 2.2 over 5100 miles, which I interprete as good TBN retention. I won't look at TAN , if any, and agree with BStone OCI could be extended further to 7000 miles or probably beyond. Edit:The test of the pudding is in the eating, which in this case refers to (the very good) Fe wear of 5 ppm over 5100 miles.
Wear metals ppm is only a piece of the story. You will not see deposit formation in a UOA, which you get from low TBN or where TAN is higher than TBN.
Deposit formation,contents of Na,Ca,Mg etc, sludge,varnish,low TBN , high TAN,residual [email protected]*C, fuel dilution % etc are merely/strictly noises.
 
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Originally Posted By: zeng
Deposit formation,contents of Na,Ca,Mg etc, sludge,varnish,low TBN , high TAN,residual [email protected]*C, fuel dilution % etc are merely/strictly noises.
Respectfully disagree. What a dense statement.
 
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