Take your analysis results and put them on the spot, especially if you have 1k plus miles on your current oil. You averaged 1.42% dilution per 1k miles. That's a big deal, and puts you at 7.1% @ the 5k recommended change interval. That's well above the critical level if you let it go as long as Mitsubishi recommends.

I'm about to send a pair of 4.6k and 5k mile samples, and someone else had a 5k sample, so we should be able to see how bad going the full recommended term is. I'm changing the next time at 2k

I agree the 3 visit stipulation is stupid, especially when we know that Mitsubishi's not doing anything at this time.

 

[ They refer to it as a "fuel diluting monster" because it had fuel up to 2.26%. But that is half of what some of you are seeing with the EVO X !


Don't BMW's have infrequent oil change intervals like 10K miles (since they service it for free presumably they are more parsimonious with maintenance expenses than an enthusiast who wants to own his car forever). If so, and they were diluting at that rate 2+ % per 1K , wouldn't that be disastrous (assuming dilution is linear/cumulative with usage). Are they blowing engines because of this ? I don't pretend to know much about the mechanics & chemistry of this, just taking a data point to it's logical conclusion.

 

".........RLI BIOSYN is the only oil I am seeing work well in DI RS4 or2.0 Audi [/B][/B]or the BMW bi turbo 3.0 I6 in the 335I. They both are killing every oil I used to recommend. I am not kidding and have no interest in promoting one oil over the other. "

Well , when I did the "smell" test , I compared to the wife's VW 2.0T (the "control group") and they both smelled somewhat like fuel so I assumed it was just me being paranoid when maybe the 2 VW engine was equally culpable as the Mitsu

 

Well, I guess you will need to "join the party" (aka Die Hard 1) like the rest of us. As you saw earlier, other brands of cars vis., Audi, BMW, SUBY have significant fuel dilution as well as Mitsu so it appears to be an endemic problem for many cars; in addition I think that one does not have to get on the car when it is cold for the fuel to enter, rather I think a significant amount may be entering during the warm up period driving moderately. But this is speculation; I have a query in to an engine builder very knowledgable of this issue in Audi's and will post if I find out anything significant. The query put into my local Mitsu rep. has not been addressed as of yet; I called again today.
In the mean time to your question, what to do given the warranty period is closing. I think we need to get at least ~10 cars sampled to provide sufficient documentation that will convince Mitsu that there is a problem. If we can accomplish that i.e., get them to agree that there is a problem not associated with individual drivers, then I think the next approach would be to ask for their help in identifying the cause(s) with associated remedies as the next step. In short, a non-confrontational approach is better than getting on them with some "heavy artillary" for this approach will only put them in defensive mode. We could be surprized if they, for example, state that these levels are not a serious problem, then at least we have their word on it and if anything happened down the road, such documentation would be of value for any future actions. As I have said earlier, it is in both Mitsu and our interest to find the cause of this problem and fix it for no one wants this problem to deter future sales of this great car, now do we?

Later, Ken

 

Fuel does not necessarily accumulate in the sump at a linear rate with mileage. Fuel dilution per 1K miles can be a misleading calculation.

Look at this data from the Audi RS4, where he pulled a sample at 4 different intervals on the same batch of oil in his sump:

@537 miles, fuel=1.72%

@1086 miles, fuel=1.65%

@1633 miles, fuel=1.70%

@2923 miles, fuel=2.0%

2923 miles is 5.4X greater than 537 miles, but the fuel dilution increased by only a factor of 1.2X

http://www.bobistheoilguy.com/forums...93022&fpart=38

 

Shouldn't this be made into a sticky, or more public somehow, so Mitsu can make a comment?

 

Now that... I find interesting. Why would the fuel enter the oil more rapidly during the first 500 miles after the oil change than on the next 2500 miles unless driving habits were changed? That to me is perplexing. Good info though, thanks.

 

Me too. I would imagine that the amount of dilution occuring per mile has to do with the cause. If it's cold starts, for example, then the number of miles between cold starts would factor in. With this in mind, I assumed the number of starts per 1k miles is going to be relatively consistant for each driver: Drive to work, drive home, go to mall, etc. I'm interested to see why that is not the case.

Does the increasing amount of fuel in the oil actually help protect the oil from further dilution?

 

Is it possible the high dilution in the first 500 miles could have been from the previous oil leftover in the lines etc?

Not really right? Because that much gasoline in the oil should have also come out

 

Fuel in oil is probably not as simple a phenomenon as it seems. It can go up with mileage, stay the same, or even go down. It will be heavily influenced by vehicle usage patterns, I would guess. Maybe one of you should consider doing a UOA at 500 miles and 2000 miles?


Here is an example, from a 2003 Ferrari 575 Maranello, where fuel went down from 3.5% to 1%, after a 2 hour highway drive:

__________New __________Ferrari_______
______0W-20 Mobil 1 ___With 3,000 Mi __With 4,000 Mi on the same oil
.................................................. .................................................. ............
Iron__________<1__________11__________13
Chromium _____<1__________<1_________<1
Nickel ________<1___________7__________8
Aluminum ______3__________10___________9
lead __________<1__________2__________2
Copper ________<1_________16__________13
Tin ___________<1__________<1 _________<1
Silver ________<.1__________<.1 ________<.1
Titanium ______<1__________<1 _________<1
Silicon ________4___________10__________8
Boron ________247_________220_________178
Sodium _______15__________15__________15
Potassium ____<10_________<10_________<10
Molybdenum __ 164_________141_________86
Phosphorus __1375________ 1353________1243
Zinc ________ 1328________1313________1169
Calcium _____ 3456________3143________2742
Barium ______<10_________<10 _________<10
Magnesium ____53_________154_________111
Antimony _____<30________<30 _________<30
Vanadium _____<1_________<1 __________<1
Fuel %Vol _____0__________3.5__________1.0
Abs Oxid ______?__________48__________28
Abs Nitr _______?__________13__________4
Wtr %vol ______0_________<.1 _________<.1
Vis CS 100C ___9.0________8.1 _________8.3
SAE Grade ____20_________20 __________20
Gly test ______NEG_______NEG _________NEG
TBN _________9.87_______not done_____not done


What happened between 3 and 4 thousand miles on the same oil is that I went on a 2 hour highway trip to help burn off fuel. Note the fuel dilution went from 3.5 to 1.0 percent. The viscosity change was 0.2.


http://www.bobistheoilguy.com/forums...310366&fpart=1

 

Sub, I think one has to keep in mind that some variables in the engine oil are dynamic while others accumulative. Fuel in the oil is dynamic, that is, there is an input and output going on all the time; input during warm up, output from exchange with air in the crank case when the oil is hot. Fe, Al and Pb by contrast accumulate within the engine over time, presumably from wear. Some of the variation is in the analysis, e.g., Al at 3K vs 4Kmi is probably just analysis error. That said, I do not understand the drop in some variables, e.g., Molybdenum unless some of the constituents originally added to the oil are "coating out" within the engine.
Now according to John Browning (Post 1175203, bobistheoilguy) , as long as Fe and Al < 30 (ppm?) and Pb < 15 (ppm?) and "other metals" stay in single digits for 10K mi ..."that engine should live a long and healthy life". I assume "other metals" are those indicative of wear and that accumulate. Now you say, Who the Hell is John Browning and what does he know"? Can't answer that other than to say it is info that should be verified for it suggests that while dilution occurs, the engine wear is perhaps acceptable.

Later, Ken

 

I'm creeping ever closer to 1k

 

I am getting a 3000 mile oil change thursday, will send a sample to Blackstone and mention the fuel smell to the service advisor. Have 11,300 miles on a bone stock GSR (factory reflash). Will post results when I get them. Let's keep the data points coming in guys, thanks for all you are doing about this.

I do think thre is something to the notion that the fuel is distilled out during long drives. To you guys with the %>4: how long is your average trip? I mostly run mine about 50 miles at a time (long commute), so we'll see if that correlates with a lower %.

 

I would say 80% or more of my trips are 15 minutes, 10 mile trips.

 

I looked into the Audi RS4's fuel dilution problems in the hopes that their causes might be similar to ours in the 4B11T engine. In short, it appears that they are not related from a fuel delivery/management point of view. The Audi RS4 engine is a direct injection engine; ours is an indirect injection. One thesis, provided by a Brit, for the former was North American models lacked the "stratified" or ultra lean burn program because a special three way Cat could not tolerate the high sulphur (30 ppm) fuels of North America resulting in over fueling of the FSI (Fuel Stratified Injection) engines. He concluded that this is the reason for the fuel dilution differences existing between North America (high)and Europe (low) models of the Audi RS 4. In passing, it appears this would be true for any imported direct injection engine since the source of the problem, namely fuel is country based. Along these same lines, Japan was shooting for their refineries to reach 10 ppm sulphur by 08; wondering whether some of our OEM "tune" issues (very rich) was also a result of the sulphur differences and its relation to NOX emmisions (rich =low NOX; lean= high NOX). Sorry, a bit off topic

Later, Ken