Is fuel dilution permanent?

[Merkurwwu]

I found this thread when looking for answers to my question and, oddly enough, it's another S60 (although mine is a turbo) and I came up with a question;

http://theoildrop.server101.com/forums/s...true#Post944161

Say you get some fuel dilution becuase, in my case, you have a weird commuting schedule sometimes and the car doesn't get a chance to run at operating temperature for longer than a couple minutes and you know the car has an aggressive fuel map. If you run the car for an hour or so at operating temperature (say you have a long commute), will you "burn" the fuel out of the oil like you do with something like condensation?

I'm wondering becuase in my S60, I drive one week with carpooler 17 miles one way to work- plenty of time to get to operating temperature. The following week, when the carpooler drives his car, the S60 only gets used for little errands to the store, the gym, etc. The S60's oil smells somewhat like it has fuel in it, much more so than the other cars, even after a long drive (like today I ran it 150 miles for work). So, is fuel dilution reversible or am I subject to more frequent oil changes because of it?

(note- I haven't done a UOA yet on this car. It has 2700 miles on it now and these are just little "driveway" observations.)

 

[gedcruise]

I would think that fuel would evaporate from the oil as higher temps are reached. Water should be easier to get rid of, since it is not soluable in oil, while fuel is. Nonetheless, I would think that the fuel would be a light fraction in the oil, and would therefore evaporate as higher oil temps are reached.

 

[JAG]

The chemical damage it causes to the oil is permanent. Yes it requires shorter OCIs relative to if there were less fuel that ended up in the oil. What that safe interval is requires a UOA with TBN to determine.

 

[Merkava_4]

Quote:

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The S60's oil smells somewhat like it has fuel in it, much more so than the other cars,

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Everyone's oil will smell like fuel usually by the next day after an oil change; it's just a cruel fact of life. I'm surprised the oil companies haven't come up with a fragrance for the oil to counteract that effect. Just as long as they don't make it smell like Marvel Mystery oil; that stuff smells just like Pepto-Bismal.

 

[Merkurwwu]

Quote:

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The chemical damage it causes to the oil is permanent. Yes it requires shorter OCIs relative to if there were less fuel that ended up in the oil. What that safe interval is requires a UOA with TBN to determine.

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Thanks. That's what I was looking for. I did't know if the fuel was "dissolved" in the oil or if it reacted with the oil to change the chemical makeup of the solution.

As for fragrance of the oil. That's as interesting idea. Hmmm. I wonder if you could make your oil smoke smell like roses

But what I was getting at was that the Volvo's oil smells like it has more gasoline in it than the other cars.

 

[Merkava_4]

What happens if you let it idle for about 25 minutes and get it nice and hot, does it still smell like fuel then?

 

[Syntec-Man]

the volvo is a turbo rite?

 

[Gary Allan]

There are surely components in the oil that will volatilize with normal (100C+/-) oil temps. I'm sure that other components hang around or would require higher temps to evaporate.

 

[G-MAN]

I think the oil smelling like raw gas can be deceptive. Example: The oil that comes out of my Olds van always smells a little like gas, but the UOAs always show relatively low fuel dilution. On the other hand the oil that comes out of my 300M never smells like gas but the UOAs always show relatively high fuel dilution.

 

[Terry]

Most newer cars are using a fuel map schedule that is designed to flush or wash out NOx emissions by a delicate balance of a metered "puff" of fuel being introduced. This has a physical liquid washing effect while lighting off the healthy properly working 3 way CAT and gaining excellent emissions reductions. However, if the design is not quite perfected or there is ANY other variable that throws the schedule or combustion chamber seal off you end up with what most are seeing as excess fuels or aromatics in the sump motor oil.

Honda was the first to try this and all are following.

Depending on the chemistry of the fuels it can have BOTH permanent and temporary damage effect on the host motor oils. It is very complex and hard to measure. However our new Premium analysis service measures all the normal wear indicators, oil adds, AND to measure this effect, FTIR fuels, oxidation, nitration, vis at 40C and 100C ( in cSt units), VI, sulfation ( a critical byproduct of fuels dilute) and closed cup flash ( more critical than open).

Therefore I can tune the application more accurately and in general get that fuel flushing design to operate more efficiently by using less fuel flushes and getting YOU more MPG. There are tricks and techniques I share only with my customers to accomplish this. Each fuel system and engine is a bit different in finding the "sweet spot".

Honda Odyssey 3.5 is very difficult to compensate for but we are working on it.

Another option that is a part of our answer, list volvo folks...is to find a aromatically resistant motor oil. RLI may be the closest answer to that without adding correction fluids and chemistries to existing formulas.

Many of the purported top of the line "synthetics" are terrible at resisting the aromatics attack. No names mentioned but M1 is the worst offender in current formulation. And the main reason for their UOA wear values being higher particularly in iron readings.

Terry

 

[ThirdeYe]

Terry - Very interesting about Mobil 1's higher iron, I've always wondered why it was like that. You really know your stuff

If/when I ever need insight into what's happening with my car I'll definitely have to utilize your expertise.

 

[JAG]

M1 has shown high iron trend in UOAs since I started looking at UOAs which was when API SJ was replaced by API SL. In my opinion, dino oils right now show the lowest wear metals in UOAs when they are not run too long. I'd say the shabbier the oil (e.g. Supertech), the better the wear metals. Should we then conclude dino oils provide not only the cheapest price but also the best wear protection when the UOA wear metals are amazingly low. Me thinks not. Me thinks wear metals levels in UOAs do not provide a clear wear picture.

I get a kick out of the excuses that were made for Redline's many not so pretty UOAs but when it's M1 that's doing it, it's bad wear...one of the worst. I've criticised Redline but not because of a concern about wear.

 

[buster]

JAG does make some good points.

 

[itchrelief]

Well there are two assumptions going on here.

One is that metals in the UOA correlate to and are proportional to engine wear.
Which may or may not be true.

The other is that synthetics are always better than dino for wear.
Which may or may not be true.

As a non expert in the field, my guess is worthless.

 

[G-MAN]

Quote:

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Most newer cars are using a fuel map schedule that is designed to flush or wash out NOx emissions by a delicate balance of a metered "puff" of fuel being introduced. This has a physical liquid washing effect while lighting off the healthy properly working 3 way CAT and gaining excellent emissions reductions.

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Is this "puff" only at start up to get the cat up to operating temp more quickly?

 

[Merkava_4]

Quote:

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Another option that is a part of our answer, list volvo folks...is to find a aromatically resistant motor oil. RLI may be the closest answer to that without adding correction fluids and chemistries to existing formulas.

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Just wondering what RLI is Terry?

 

[Terry]

No Gary that is normal CAT light off design. I am talking systemic and cyclic variations to fuel map.

JAG and buster as usual you are both misinformed and somewhat misguided and very proud to share it!

While I share public commentary on spectral UOA which is the dominant test format "studied" here, rest assured I base my determinations on more than BITOG procured UOA testing data and when the API SJ to SL switchover took place.

JAG, No offense intended , In other words you should not conclude anything without more education and insight into tribology as it relates to liquid lubricants! Testing protocols are critical to understanding and back yard oil boilings are not normally controlled enough to gain that kind of insight!

TD

 

[Terry]

RLI = Renewable Lubricants Incorporated of "supersecret" BIOSYN fame. When Specialty Formulations went off line this is where we must head to get cutting edge BIO AND SYN formulas that to date seem to resist aromatics damage better than current formulas.

 

[JAG]

Terry, you shouldn't make big statements and then when questioned, resort to mud slinging. Making big statements is fine but you should be prepared to provide specifics about how you or whoever it was came to those conclusions. You think that you are to be taken on your word but it doesn't work that way in the scientific world.

 

[bulwnkl]

JAG, I understand your point because I am in that world almost daily, but honestly: Is BITOG really the "scientific world" (though I WISH it was more than it is)? Is someone in Terry's position expected to give away everything that gives them their business for the sake of back yard "peer" review? Give me a break. Do some business with him and see whether he knows what he claims to know, but don't instigate the mud-slinging and then cry foul when someone won't just give you their business secrets for the fun of it.