Mobil1 SS 0w-40 - 5169 miles - '01 A4 1.8T

[Quattro Pete]

Well, after a number of other Audi owners' UOAs that I posted, I finally managed to get another UOA from my own A4. I'm not too happy about the fuel dillution in this one... I'm including my earlier UOA as well for comparison.

code:

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Lab: Dyson Analysis Blackstone Labs



Oil Brand/Weight : M1 SS 5w-30 M1 SS 0w-40

Miles on oil : 4 725 5 169

Total Miles : 19 976 33 332

Oil in date : 25 Jul 2002 20 Jun 2003

Oil out date : 12 Nov 2002 11 Jun 2004

Driving conditions: 75% city/25% hwy 80% city/20% hwy



Results (ppm/%)



Aluminum 4 3

Chromium 1 1

Iron 16 24

Copper 6 9

Lead 3 1

Tin 0 9



Molybdenum 65 58

Nickel n/a 1

Manganese n/a 1

Silver n/a 0

Titanium n/a 0

Potassium 0 1

Boron n/a 92

Silicon 10 12

Sodium 7 5

Calcium 2340 2521

Magnesium 185 215

Phosphorus 730 702

Zinc 850 897

Barium n/a 0



Water (%) negative 0.0

Fuel (%) negative 1.0

Antifreeze (%) negative 0.0

Soot/Insolubles 0 0.2

TBN 6 4.1

Vis@100 C 9.8 67.8 (12.4 cSt)

Flashpoint (F) n/a 355

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Additional bits of information about this interval:
- this was my second run with M1 SS 0w-40
- oil was in service for an entire year
- car is now chipped, so it's working harder than before
- OEM oil filter
- OEM air filter (new one was installed in June 2003)
- quite a lot of cold starts and relatively short trips
- car sat unused for about 1.5 months last summer while it was being shipped from US to Poland
- gas is of questionable quality here in Poland (unscrupulous gas station owners often dillute it with all kinds of crap), but I haven't noticed any rough engine behavior as of yet
- brand new coilpacks were installed in June 2003, so it's probably not them that caused the fuel contamination, but who knows?

Questions? Comments?

 

[Geoff]

Perhaps the fuel dilution is due to the long period over winter, when the car ran rich more often. Did you get it hot long enough to burn off the fuel? The new chip might be richening the mixture for more power also.

 

[Quattro Pete]

Yeah, I thought about that, but then wouldn't there also be moisture present (water)? But no, I tried limiting short trips to a minimum and making sure that the car gets hot long enough at least once a week. It was only getting used twice or three times a week anyway.

 

[Patman]

That tin is kinda scary! The lab I use flags it at 10ppm or higher.

 

[Terry]

Fuel dilution and bearing overlays don't like each other Pat !

 

[Patman]

quote:

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Originally posted by Terry:
Fuel dilution and bearing overlays don't like each other Pat !

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I didn't think only 1% fuel would do that much damage though. My UOA from Winter 2002/03 showed 1.0% fuel in my Firebird, but less than 1ppm of tin.

 

[Terry]

Pat, apples and oranges on engine construct and reasons for dilution.

You can't compare a LT1 in Canada to the 1.8L Turbo hummer.

I think all your Sn bearing overlay/alloy is gone on that car !!!

Just kidding.

Terry