2019 Mazda CX-5 2.5T M1 5w30 7422 mi

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Last UOA is here. On the one hand, I feel kind of silly changing out Mobil 1 at 7400 miles. On the other, my viscosity had already hit the bottom end of 5w30 range in that usage. New fill is Meijer (Warren) synthetic 5w30. [Linked Image]
 
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Looks good to me. Copper should keep going down. Why is it thinning out without any fuel dilution?
 
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Blackstone cannot measure the presence of fuel, so please do not pay attention to their fuel % on the report.
 
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Nice report. I also have a 2019 CX 5 with the turbo engine. I am running Castrol Edge 5W-30 but do not intend upon going more than 5000 miles between changes. Partly because I make a lot of short trips so probably qualify under the severe service category and partly because I like to err on the side of caution with regards to possible fuel dilution. I will run a Blackstone report at the 10,000 mile point once the engine is well broken in and see how my plan is working.
 

JOD

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I suspect there's fuel in the oil. Considering the high flashpoint of the the oil (230C), I don't think it precludes there being fuel in the oil. I'd suggest having it tested somewhere that actually tests for fuel dilution--and if there's a significant amount in there I'd probably keep the OCI where it is.
 
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Originally Posted by drtyler
Blackstone cannot measure the presence of fuel, so please do not pay attention to their fuel % on the report.
Originally Posted by JOD
I suspect there's fuel in the oil. Considering the high flashpoint of the the oil (230C), I don't think it precludes there being fuel in the oil. I'd suggest having it tested somewhere that actually tests for fuel dilution--and if there's a significant amount in there I'd probably keep the OCI where it is.
Is it actually documented that Blackstone can't measure fuel content? I don't mean to come off as accusatory, so I apologize if anyone gets that impression. When two people say it, though, I get curious.
 
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Originally Posted by leeharvey418
Is it actually documented that Blackstone can't measure fuel content? I don't mean to come off as accusatory, so I apologize if anyone gets that impression. When two people say it, though, I get curious.
Yes, because they don't measure it directly and try to infer it based on their own flaky measurments. We have had multiple UOA posted here that when retested at a lab that uses gas chromatography they obtain vastly different fuel dilution results. Flash point measurement has a high reproducibility value and is not precise. I haven't seen much that Blackstone measures well, from the ICP results to flash point to viscosity.
 
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Why doesn't someone email blackstone and ask about their fuel finding accuracy. A lot of wild claims on this forum on how Blackstone doesn't know what they're doing when measuring fuel in oil coming from people who have probably never stepped foot inside their lab or A lab to begin with.
 
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Originally Posted by jayjr1105
Why doesn't someone email blackstone and ask about their fuel finding accuracy. A lot of wild claims on this forum on how Blackstone doesn't know what they're doing when measuring fuel in oil coming from people who have probably never stepped foot inside their lab or A lab to begin with.
Wild claims? What are you talking about? We have seen numerous UOA retested by a lab that show wildly different fuel dilution values when directly measured. And I worked in a corporate research laboratory for many years as a research technologist, as well as earned my minor in chemistry by working for a college chemistry lab for several other years. I've "stepped foot" in them many times and ran many of the same tests on used oils. Blackstone's estimation of fuel dilution is not reliable.
 
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I would not go much past 7500 miles on Mobil1 "vanilla" for a forced induction DI engine, especially if you like to get on the vehicle.
 

JOD

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Originally Posted by jayjr1105
Why doesn't someone email blackstone and ask about their fuel finding accuracy. A lot of wild claims on this forum on how Blackstone doesn't know what they're doing when measuring fuel in oil coming from people who have probably never stepped foot inside their lab or A lab to begin with.
They aren't "wild claims". The do not directly measure fuel dilution on a standard UOA, period, end of story. You can contact them directly and ask them yourself, but this is not new news. They estimate fuel dilution based on FP and viscosity drop. It's been demonstrated several times that this is not a reliable method. If you want to actually know how much fuel is in the oil, you have to test for it. There are other services that do perform the test. This should maybe help with some of the different methods for measuring and estimating fuel dilution: https://www.machinerylubrication.com/Read/31148/fuel-dilution-tests I believe that Blackstone can perform a GC test--you just have to pay for it.
 
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