High Fuel% 2013 Mazda CX-5 2.0 Skyactiv 40579mi

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I'm seeing high fuel percentage in my UOA from Blackstone. This car resides garaged in San Diego and is primarily a highway commuter or long roadtrip car; not exactly severe usage. I'm concerned about potential buildup on the valves since this engine is DI. I know Blackstone's flashpoint methodology is rather rudimentary, but I'm assuming the percentage is quite high regardless of any error margin (3.3% and 2% in my most recent samples).

Side note: I ditched factory fill after warranty period. I've been using Castrol 0w20 w/ Titanium with the hope of increasing change interval; did I get cheated on the 33k fill (ie did they put in the standard synth)? Far higher percentage of Ti on second sample, and I watched that one go in.

Until I get the fuel problem resolved I'm going to be using standard synthetic. Switching to 91-octane based on suggestions from this forum to see if that improves the issue.

Any feedback is appreciated. Is this common w/ DI? w/ Skyactiv?

Code:


OIL CASTROL SYNTEC TITANIUM 0w20

MILES IN USE 7.5k 7.0k

MILES 40.6k 33.0k

SAMPLE TAKEN 10/30/14 5/21/14



ALUMINUM 3 3

CHROMIUM 0 0

IRON 7 8

COPPER 0 1

LEAD 1 1

TIN 0 0

MOLYBDENUM 79 87

NICKEL 0 1

MANGANESE 0 0

SILVER 0 0

TITANIUM 28 1

POTASSIUM 3 4

BORON 26 28

SILICON 9 7

SODIUM 7 11

CALCIUM 776 895

MAGNESIUM 1374 1111

PHOSPHORUS 602 593

ZINC 796 774

BARIUM 0 0



INSOLUBLES 0.3 0.2

WATER 0 0

FLASHPOINT ºF 320 345

SUS VIS 210ºF 50.4 48.2

cSt @ 212ºF 7.38 6.72

FUEL% 3.3 2.0

TBN 4.6 5.6


2013 Mazda CX-5 Touring AWD
 
Hmmm, did you get cheated(titanium) on your 33K OCI? It certainly seems that way... IDK, maybe but, it's done and gone!

Yes, very good wear numbers!

Your TBN is still 5.6/4.6 which is very good for an OCI w/7.0K/7.5K miles respectively! And all other numbers are quite close considering that both OCI's are most likely from different batches of the same oil(Castrol SynTec w/Titanium).

And too, your 33K mile OCI did sheer more with fewer miles but, that could be from a variety of factors that we're unaware of.

Your Calcium/Magnesium numbers look switched with one another but, I may be wrong. Seems as though they should be the other way around!
smile.gif


Your 40.6K OCI did show a lower TBN and Flashpoint and this could be from the higher fuel dilution and longer OCI(again, many factors).

I personally don't know what is considered high fuel dilution(fuel%).
 
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It isn't causing any harm but if you feel you want to reduce the fuel dilution, run premium entire OCI and sample again.
 
When you bring the CX5 in for a change has the car been run for awhile to get up to temp? Some recommend a highway drive of 10-20 minutes to burn off the fuel dump from a cold start. Likewise, is the car sitting for a time before the tech gets to it? A quick start/stop to pull it into the bay could also lead to a fuel spike.

Really good wear numbers, as has been mentioned, and strong tbn. Nice!
 
I forgot to add, yes it is common for the skyactiv. Only one skayctiv UOA has been posted so far with no fuel dilution issues.
 
Thanks for the feedback @k24a4! I've had both changes done right after my commute home; about 20-30 minutes largely highway, with a few city miles at the end. For this most recent change, the shop was empty, so I rolled right in w/o shutting off and the guys were draining within 5 minutes.
 
Doesnt look like its hurting anything, I wouldnt extend the oci.

Under warranty.. its not worth it. Your oil is also close to being dangerously thin.

Most likely the good wear numbers are because you aren't hard on the car.
 
The DI intake valve deposit issue is completely separate from fuel dilution. Extreme fuel dilution could result in added engine wear, but not valve deposits. Fuel dilution could theoretically reduce valve deposits as the PCV vapors would contain some fuel solvents.
 
Premium fuel will stop it from having to overfuel as much to avoid detonation.

If I was thinking, I would have pulled a UOA sample on my parents 2013 Focuscape 2.0 GTDI before and after they switched to 91 instead of 87.
 
Originally Posted By: Danh
The DI intake valve deposit issue is completely separate from fuel dilution. Extreme fuel dilution could result in added engine wear, but not valve deposits. Fuel dilution could theoretically reduce valve deposits as the PCV vapors would contain some fuel solvents.


The fuel in oil causes increased volatility and more oil vapors coming back through the PCV. It isn't direct but it does likely have an impact.
 
Originally Posted By: badtlc
Originally Posted By: Danh
The DI intake valve deposit issue is completely separate from fuel dilution. Extreme fuel dilution could result in added engine wear, but not valve deposits. Fuel dilution could theoretically reduce valve deposits as the PCV vapors would contain some fuel solvents.


The fuel in oil causes increased volatility and more oil vapors coming back through the PCV. It isn't direct but it does likely have an impact.


Well, except that the most volatile elements (fuel) will be evaporating. Don't know it necessarily follows that oil would attach and evaporate as well.
 
Originally Posted By: Danh
Originally Posted By: badtlc
Originally Posted By: Danh
The DI intake valve deposit issue is completely separate from fuel dilution. Extreme fuel dilution could result in added engine wear, but not valve deposits. Fuel dilution could theoretically reduce valve deposits as the PCV vapors would contain some fuel solvents.


The fuel in oil causes increased volatility and more oil vapors coming back through the PCV. It isn't direct but it does likely have an impact.


Well, except that the most volatile elements (fuel) will be evaporating. Don't know it necessarily follows that oil would attach and evaporate as well.


They are both hydrocarbons. They will mix and react to a certain extent.
 
Update to OP: I switched to premium for the entire oil interval, and my dilution is down below measurable levels. Blackstone didn't have an explanation as to why that might be, but admitted it looks like whatever was causing it has gone away. Not likely to occur with a mechanical issue. Looking to repeat this interval, will post.

Side note: I do see elvated levels of Boron and Calcium, and a severe drop in Magnesium. No mention by Blackstone; any thoughts on what those might be?

Html:


OIL 0w20SYNTEC CASTROL SYNTEC

NO TI TITANIUM 0w20

MILES IN USE 8.1k 7.5k 7.0k

MILES 48.7k 40.6k 33.0k

SAMPLE TAKEN 3/30/15 10/30/14 5/21/14



ALUMINUM 4 3 3

CHROMIUM 0 0 0

IRON 6 7 8

COPPER 1 0 1

LEAD 0 1 1

TIN 3 0 0

MOLYBDENUM 76 79 87

NICKEL 1 0 1

MANGANESE 0 0 0

SILVER 0 0 0

TITANIUM 10 28 1

POTASSIUM 2 3 4

BORON 94 26 28

SILICON 8 9 7

SODIUM 5 7 11

CALCIUM 1838 776 895

MAGNESIUM 236 1374 1111

PHOSPHORUS 677 602 593

ZINC 779 796 774

BARIUM 0 0 0



INSOLUBLES 0.1 0.3 0.2

WATER 0 0 0

FLASHPOINT ºF 380 320 345

SUS VIS 210ºF 50.5 50.4 48.2

cSt @ 212ºF 7.41 7.38 6.72

FUEL% TR 3.3 2.0

TBN NO TEST 4.6 5.6
 
The wear numbers are quite good and the 210 viscosity is also good. Therefore I would not be concerned but, possibly question the Blackstone fuel percentage.
 
"Side note: I do see elvated levels of Boron and Calcium, and a severe drop in Magnesium."

- different add pack, no worries. Those are some outstanding wear #'s for an 8k run. I'd go back to regular gas and see what happens - I'd hate paying the extra for premium. Thanks for posting
 
Mazda needs to solve their fuel dilution in these engines. Great concept with a 13:1 compression ratio on regular for increased mileage. But this is the result... and I suspect the mileage is not as good as they claim as a result of running these engines so rich.
 
Originally Posted By: vincegt
Update to OP: I switched to premium for the entire oil interval, and my dilution is down below measurable levels. Blackstone didn't have an explanation as to why that might be, but admitted it looks like whatever was causing it has gone away. Not likely to occur with a mechanical issue. Looking to repeat this interval, will post.

Side note: I do see elvated levels of Boron and Calcium, and a severe drop in Magnesium. No mention by Blackstone; any thoughts on what those might be?

Html:


OIL 0w20SYNTEC CASTROL SYNTEC

NO TI TITANIUM 0w20

MILES IN USE 8.1k 7.5k 7.0k

MILES 48.7k 40.6k 33.0k

SAMPLE TAKEN 3/30/15 10/30/14 5/21/14



ALUMINUM 4 3 3

CHROMIUM 0 0 0

IRON 6 7 8

COPPER 1 0 1

LEAD 0 1 1

TIN 3 0 0

MOLYBDENUM 76 79 87

NICKEL 1 0 1

MANGANESE 0 0 0

SILVER 0 0 0

TITANIUM 10 28 1

POTASSIUM 2 3 4

BORON 94 26 28

SILICON 8 9 7

SODIUM 5 7 11

CALCIUM 1838 776 895

MAGNESIUM 236 1374 1111

PHOSPHORUS 677 602 593

ZINC 779 796 774

BARIUM 0 0 0



INSOLUBLES 0.1 0.3 0.2

WATER 0 0 0

FLASHPOINT ºF 380 320 345

SUS VIS 210ºF 50.5 50.4 48.2

cSt @ 212ºF 7.41 7.38 6.72

FUEL% TR 3.3 2.0

TBN NO TEST 4.6 5.6


Did you track your gas mileage between 87 and 91 octane? I have a feeling you're going to get your money's worth with this engine.
 
Originally Posted By: webfors
Originally Posted By: vincegt
Update to OP: I switched to premium for the entire oil interval, and my dilution is down below measurable levels. Blackstone didn't have an explanation as to why that might be, but admitted it looks like whatever was causing it has gone away. Not likely to occur with a mechanical issue. Looking to repeat this interval, will post.

Side note: I do see elvated levels of Boron and Calcium, and a severe drop in Magnesium. No mention by Blackstone; any thoughts on what those might be?

Html:


OIL 0w20SYNTEC CASTROL SYNTEC

NO TI TITANIUM 0w20

MILES IN USE 8.1k 7.5k 7.0k

MILES 48.7k 40.6k 33.0k

SAMPLE TAKEN 3/30/15 10/30/14 5/21/14



ALUMINUM 4 3 3

CHROMIUM 0 0 0

IRON 6 7 8

COPPER 1 0 1

LEAD 0 1 1

TIN 3 0 0

MOLYBDENUM 76 79 87

NICKEL 1 0 1

MANGANESE 0 0 0

SILVER 0 0 0

TITANIUM 10 28 1

POTASSIUM 2 3 4

BORON 94 26 28

SILICON 8 9 7

SODIUM 5 7 11

CALCIUM 1838 776 895

MAGNESIUM 236 1374 1111

PHOSPHORUS 677 602 593

ZINC 779 796 774

BARIUM 0 0 0



INSOLUBLES 0.1 0.3 0.2

WATER 0 0 0

FLASHPOINT ºF 380 320 345

SUS VIS 210ºF 50.5 50.4 48.2

cSt @ 212ºF 7.41 7.38 6.72

FUEL% TR 3.3 2.0

TBN NO TEST 4.6 5.6


Did you track your gas mileage between 87 and 91 octane? I have a feeling you're going to get your money's worth with this engine.


@webfors, I do see about 2mpg better with premium. That's a loose average; I often have a bike rack up top, but for long trips it's off, which further improves my highway mpg. Using the numbers from my last two change intervals, if premium fuel is less than $0.25 more expensive per gallon, I'll approximately break even (CA gas prices). If the cost difference is greater than $0.25, it makes sense to buy regular. I haven't factored in the increased interval I'm now more comfortable with based on the elimination of dilution (pushing maybe 1000-2000 miles more), but that would save me $5-10 max, so it's pretty insignificant.

Either way I'm happy with the mpg; ~24.2 for regular, ~26.2 for premium. For an AWD crossover that doesn't stay under the speed limit, no complaints. Bigger difference is just to remove the bike rack (I see ~+3mpg w/o it) but I ride all the time so not really an option.
 
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Originally Posted By: webfors
Mazda needs to solve their fuel dilution in these engines. Great concept with a 13:1 compression ratio on regular for increased mileage. But this is the result... and I suspect the mileage is not as good as they claim as a result of running these engines so rich.


Definitely runs rich; the tailpipes are sooty inside. I have concerns for the longevity of the engine because of that. Combine EGR and DI, and your valves can build up gunk prtty quickly (no gasoline detergent to clean them). We'll see.
 
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