For those wanting to try a 5W40, Shell Rotella T 5W40 is a great performer at a price of only $19 for a 4qt jug (at Walmart). Just be sure to get the latest version, with SM and CJ-4 certification. Cheap enough to change every 3000 miles ,and even if it loses viscosity over 3000 miles, it will be a SAE30, and not a SAE20.

Here is a good UOA on the latest version of Rotella, in a Stage 2 STI:
http://www.bobistheoilguy.com/forums...361791&fpart=1

 

Peter, So from this information and NMX's results, looking at %fuel dilution is a waste of time. Rather, viscosity loss/reduction is a more accurate variable of same. In addition, it appears that our best measure of the effects of viscosity loss, that is to see if such loses are of concern, we should look at the concentration of specific metals. If correct, you have mentioned Sn, Cu and Si. What should the "no concern" levels be for these metals? And do you agree that Al, Fe and Pb, Browning's selected set of metals, should also be considered at <30, <30 and 15ppm, respectively? Thanks.

Later, Ken

 

Ken, I would not say looking at fuel dilution is a waste of time. You have to find an analyst who has experience dealing with fuel dilution, and Blackstone is not one of those places. Dyson Analysis has extensive experience, and perhaps others also. I know at Dyson they do a closed cup flash and FTIR to determine fuel, plus look at viscosity index and viscosity loss and manganese levels (and other fuel markers) to determine fuel%. Looking at viscosity loss alone will be inadequate.

Plus you have to be consistent with your sampling protocol. I always take a half hour drive on rural roads before taking my oil sample, and take the sample within 30 minutes of arriving home. If your normal routine is stop & go driving, then do a 1/2 hour of stop & go driving before taking your sample. I always clean the Fumoto drain valve with a blast of brake cleaner before opening the valve, and let about a 1/2qt of oil drain before collecting the sample.

You can find endless debate at BITOG about what is the "no concern" level for wear metals. Personally, I think that for a 3000 mile UOA, all wear metals should be well under 10 ppm. But that is just my bias. From what I have seen, oil analysis companies seem to set their "warning advisories" in the range of 20-150 ppm, depending on the specific metal.

Does the EVO X motor use a low tension ring pack on the pistons?

Peter

 

Peter, I have no idea about the ring assembly (EVO M needs EVO X Engine Build Catagory) other than it appears to have 5 rings assuming the Cosworth set for 86.5 mm bore are the same as the OEM (see http://www.bursethracing.com/product.../582/sfID2/584).
That said, Cosworth claims that the use of these rings will result in "“Oil and combustion gas control features - reduced blow-by and oil consumption” and SRP has similar verbiage with “High-silicon 4032 aluminum alloy for reduced piston-to-wall clearance and quiet operation ;Accumulator grooves for improved ring seal”. Now I do not know if this is all just "boiler plate" hype but it does suggest that blow-by may be reduced with the use of these ring sets. Just something to think about.

Later, Ken

 

All right, well I have a IX, but I just got my oil results back with a 2.8% fuel dilution.. after about 500 miles or so.. I was taking a lot of short trips etc., but I took a 200 mile trip and that was close to the most recent thing I did with the car before I sent it to oil analysis. I noticed because I was getting a burning smell from the exhaust.. I was running Amsoil SSO, but I went back to Mobil 1 EP for now, and none of those symptoms are exhibited. I think I'll send in my Mobil 1 for analysis when I'm ready.

 

Wow your SSO produced that much diluiton in only 500 miles? Hmmm

 

What do you think caused it?
I've never had a problem before with it

 

Could post up your oil analysis results? Particularly interested in metal results and viscosity reduction. Thanks.

Later, Ken

 

i dont know, i try to put here my opinion without bad mouth on anyone or anything.

I'm driving Evo's a pretty long time now.
I never had a clean oil change ... Or even clean oil after X amount of miles/between oil changes/
Fact i never worried about this thing... And so far i shouldn't. It was a same all my turboed car , including my favorite the Integrale HF Evo2.

Seems to me as more as i read this thread, like air balloon is keep blowing up and growing, but really nothing is in to it, just a thin air.
Looks like in the states, if you dont have to be afraid from something , then some one will create a cause. Kinda like a must.

I think you guys have to worried more about your set up and tune , then anything else.

I truly believe after countless pages an basically no extra ordinary engine failure, this is not an issue at all. Any engine failure i know of is related to tune- boost- driver error. And nothing to do with gas in the oil.

Thanks to reading it, and sorry i just couldnt keep it more

Rob

 

Rob, The potential outcome of oil dilution will never be engine failure but rather excessive engine wear. So to say because we have not seen engine failure there is not a problem ignors the nature of the concern. Now the current EVO owners have been told by others that anything over 2%-4% fuel dilution of the engine oil is a problem. Now I suspect Papi will say, being the sceptic that he is, this whole issue has been blown out of proportion because these same people, oil analysis companies and motor oil companies, want us to panic and start to not only change oil brands but also initiate a monitoring program both of which is in their financial interests. You, or anyone for that matter, can eliminate further debate IF you know of anyone that has experience with diluted oils and its effects on the longevity of the associated engine that will state (based upon some associated studies) that the levels the current owners have seen in their cars, and probably in yours as well, is NOT a problem, then please do so. Otherwise you are whistling in the wind.

Later, Ken

 

Ken, i'm lost here then. I would like to see clearly about this, since i never had this subject poped up before.
Which kind of engine wear can be caused by fuel dilution, will fundamentally change the engine performance later? And can be 100% identified as a fuel dilution problem?
Loss of compression?

Thanks Rob

 

Rob, the cranks bearings have very small tolerances. If there is excessive fuel dilution, the lubricating capability of the engine oil is compromised and increased wear of the bearings will occur; the same is true for your example: between the rings and cyclinder wall. In both these cases, the engine is wearing faster than it should and, yes, you will get a compression loss sooner rather than later. When the lubricating power of the oil is compromised the concentration of metals, constituents of the bearings, in the oil contained will increase over and above that when the oil viscosity has not been reduced. The engine will not fail and its performance will probably not be conpromised on our current "new" engines. However, the concern is instead of your engine being, say, a 10K mi odometer reading is actually, say, a 40K mi engine in terms of wear.
What we do know is a significant amount of fuel, according to others in the business (but see my comments earlier), is getting into the oil. Everyone knows that fuel will enter the oil of any petrol engine; the concern is the amount and is this causing excessive wear. Now for DD, it may not be an issue. That said, what about during AutoX or the track (or dare I say "sprited driving") where you are pushing the limits of the engine? Will the loss in viscosity of the oil compromise the engine under these extreme conditions? I shall put it another way: Mitsu has said use 5-30W in the 4B11. Would you put your car on the track with 5-20W? If your answer is no, then you to should be concerned over the loss in viscosity because this is the same loss that has been observed in every X measured to date.

Later, Ken

 

Thanks!!
I'm always learning. Good info's!
Rob

 

All the metal results were great/no wear, a lot of additives from the SSO, but as the fuel dilution was at 2.8%, it brought the viscosity at 100C CS to 8.5, which was of concern

 

Well, after my tune, my oil smells less strong of fuel. Obviously, my nose is only a subjective tool and the next oil analysis will tell more. I will say this though: from talking to my tuner, the issue could be cumulative from all aspects of the tune and not just WOT where the stock tune runs the richest. The fuel run off programming (enrichment when transitioning from on throttle to off) is also unusually rich on the X and drops timing to crazy low values as well. Many tuners don't bother tuning this, as they only focus on full throttle tuning and forget about everything else. This could explain why some people who are tuned are still experiencing fuel dilution issues. Who knows? We will find out soon enough I suppose. On a side note, I encourage everyone to run fuel system cleaners every oil change, because cars that run excessively rich tend to have more deposits than normal and this is good preventative maintenance.