Best oil for handling 1-3% fuel dilution

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There is no best. Your oil change interval will have more importance.

On a side note, there have been multiple uoa’s posted with high fuel dilution yet wear metal amounts were well within safe limits.
 
Originally Posted By: PimTac

On a side note, there have been multiple uoa’s posted with high fuel dilution yet wear metal amounts were well within safe limits.


I wonder if this is due to excellent "anti-wear" additive properties?

I'd love to see more testing.
 
Assume no there's no underlying mechanical problem, about all you can do for fuel dilution is a) change the oil more frequently and b) go up a viscosity grade or look for the most viscous oil available in your specified grade.

Looking at your UOAs you have a lot of fuel dilution and, based on viscosity, way more than Blackstone estimates (but Blackstone is another story on this subject).
 
Originally Posted By: Danh
Looking at your UOAs you have a lot of fuel dilution and, based on viscosity, way more than Blackstone estimates (but Blackstone is another story on this subject).


Aside from what Blackstone says, the above link shows that SUS viscosity (@ 210 F) dropped from 65 to 48, and that cSt viscosity (@ 100 C) dropped from 11.76 to 6.86. From these viscosity drops, is there any way to better estimate fuel dilution % (other than Blackstone numbers)? Anyone think I'm over 4%?
 
Originally Posted By: claluja
Originally Posted By: Danh
Looking at your UOAs you have a lot of fuel dilution and, based on viscosity, way more than Blackstone estimates (but Blackstone is another story on this subject).


Aside from what Blackstone says, the above link shows that SUS viscosity (@ 210 F) dropped from 65 to 48, and that cSt viscosity (@ 100 C) dropped from 11.76 to 6.86. From these viscosity drops, is there any way to better estimate fuel dilution % (other than Blackstone numbers)? Anyone think I'm over 4%?


Look at UOAs from Oil Analyzers, which uses gas chromatography to determine fuel dilution. My own experience with Oil Analyzers is that a 100C cSt drop of 2 full points from new yields dilution of >5% (OAI doesn't quantify values >5%). So, assuming the viscosity drop isn't from another source a drop of 4 points would be 10% or more.

I don't know much about outboard motors, but this level of dilution seems really excessive especially because this isn't a direct-injection engine. Sure there isn't another problem here like deposits on fuel injectors? Can you try a fuel system treatment like Techron on this engine? Or maybe it really doesn't like trolling?
 
A thicker (higher viscosity) oil would have room for the lowering of viscosity that fuel dilution causes.

So if normally you were running a XW-30, you might want to run a XW-40, and if you were running XW-40 you might want to run a XW-50.
 
FWIW: My turbo Optima will run greater than 5% fuel dilution (using Oil Analyzer's GC method) and I've experimented with synthetic oils M1 0W-40 (FS and non-FS versions) and now Castrol Edge 0W-40 oil. My best reports have come from running the Castrol Edge oil (w/OCI of under 5K miles).

My wear levels are very good regardless.
 
Synthetic oil is more tolerant of fuel dilution. For example, see:

http://www.boats.com/reviews/the-outboard-expert-outboard-oil-facts-and-myths/#.WkqwiHNOnqA

A certification under FC-W requires an HTHS of at least 3.3 cP, which most other xw30 oils don't meet. FA-4 HDEOs, for example, have HTHS of 2.9-3.2.

So, for now, due to the expected fuel dilution, thinking of reducing OCI intervals, and sticking with synthetic Yamalube 5w30 (OEM rec) which is FC-W certified.

Will also get a new lab (preferably Oil Analyzers) to handle next UOAs for this pair of engines, to get a better handle on fuel dilution percentage.
 
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Originally Posted By: claluja
Synthetic oil is more tolerant of fuel dilution. For example, see:

http://www.boats.com/reviews/the-outboard-expert-outboard-oil-facts-and-myths/#.WkqwiHNOnqA

A certification under FC-W requires an HTHS of at least 3.3 cP, which most other xw30 oils don't meet. FA-4 HDEOs, for example, have HTHS of 2.9-3.2.

So, for now, due to the expected fuel dilution, thinking of reducing OCI intervals, and sticking with synthetic Yamalube 5w30 (OEM rec) which is FC-W certified.

Will also get a new lab (preferably Oil Analyzers) to handle next UOAs for this pair of engines, to get a better handle on fuel dilution percentage.


Pick an ACEA A3/B3/B4/C3/C4 xw30 or CJ-4/CK-4 xw30. You'll get a higher HTHS.
 
Actually someone did find some boutique oils like bio syn? Resisted fuel dilution very well. Can't remember the name of it but there was a user spouting off about it and a number of things and people got sick of some of his comments. His UOA however did show some of the lowest dilution in a turbo DI car and he used a lab with GC testing.

Blackstone fuel numbers can't be trusted. If they say there's X amount of fuel, it's almost always way more and the viscosity does look really low. If the engine is port injected then something may be wrong.
 
Originally Posted By: KL31
Actually someone did find some boutique oils like bio syn? Resisted fuel dilution very well. Can't remember the name of it but there was a user spouting off about it and a number of things and people got sick of some of his comments. His UOA however did show some of the lowest dilution in a turbo DI car and he used a lab with GC testing.

Blackstone fuel numbers can't be trusted. If they say there's X amount of fuel, it's almost always way more and the viscosity does look really low. If the engine is port injected then something may be wrong.

I've been looking for details on how RLI is supposed to handle fuel better for a while now, but can't find the details. A few good threads can be found with a google search.

I like this from edhackett:
Quote:
The unsaturated aromatic hydrocarbons in the fuel react with the base oils and VIIs and permanently shear them. The sheared ends then oxidize. The oil is permanently damaged and can not be restored by getting it up to temperature. The damage does effect the ability of the oil to lubricate.

What you would see in UOA would be lower viscosity, lower HTHS, high oxidation, and rapid TBN depletion compared to an oil not subjected to excessive fuel dilution. Keeping the OCIs short is the only way to mitigate the effects of fuel dilution.

High quality HDEOs seem to be able to better withstand the effects of fuel dilution better than standard PCMOs.

From this thread:
https://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2752927

Some quotes in here from Terry Dyson:

https://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1308021

And I do not recall if there are more details about how RLI is supposed to help in one of the original RS4 threads (haven't read through this lately):

https://bobistheoilguy.com/forums/ubbthreads.php/topics/1173821/1
 
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Bluesubie - good reads, thanks for posting.

Complicated issue. Seems like (1) synthetics are more tolerant of fuel dilution compared to dino, (2) short OCIs are key, (3) ethanol in fuel can increase fuel dilution, and (4) high HTHS and HDEO oil is good for dealing with dilution. Appears as if there are disputes on whether thin or thick oil is better able to handle fuel dilution.

I don't have the stones to run RLI in these engines. Mfg also doesn't like too much P in the oil for these engines, which leads me away from some HDEOs. But the lower P HDEOs also seem to have lower HTHS. Seems like best bet in my mind is synthetic, relatively high HTHS, ethanol free gas if possible, short OCIs, and monitor with Oil Analyzers UOAs . . .
 
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An E6 HDEO like Shell Rotella T6 Multi-Vehicle 5w-30 or Delvac 1 LE 5w-30 will have the elevated HTHS of 3.5 or greater with a maximum phosphorous of 800 ppm. Both are also SN, of course.
 
Here's the guy using the bio syn I was talking about. He was in a lot of arguments with people here. Someone called [censored] on his mileage in this thread but I don't see why he'd lie. Also correlates with that Audi dilution thread where they used RLI and had less dilution.

https://bobistheoilguy.com/forums/ubbthreads.php/topics/4538224/2015_Lexus_RC-F_10,000_mile_OC#Post4538224

Another of his UOAs here https://bobistheoilguy.com/forums/ubbthreads.php/topics/4492189/BioSyn_HD;_5k_miles;_Lexus_RC_#Post4492189

He said that usually dilution is at 3-4% on his engine type but he had both UOAs show far lower than that. He mentioned something about the Bio Esters resisting fuel better.

Also, I think using higher quality fuel helps too. Might make certain car's ecus run less rich etc. I wouldn't fear using if others have used these oils in Lexus and Audi turbo direct injections with good results. Worth a shot to see if it lowers FD on more vehicle makes and models.
 
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Originally Posted By: KL31
Here's the guy using the bio syn I was talking about. He was in a lot of arguments with people here. Someone called [censored] on his mileage in this thread but I don't see why he'd lie. Also correlates with that Audi dilution thread where they used RLI and had less dilution.

https://bobistheoilguy.com/forums/ubbthreads.php/topics/4538224/2015_Lexus_RC-F_10,000_mile_OC#Post4538224


I checked with the "mentor" that he mentioned in many threads to see what his actual story was...less than savory.
 
Originally Posted By: Shannow
I checked with the "mentor" that he mentioned in many threads to see what his actual story was...less than savory.


Interesting. Every time he was questioned on his sources/data he acted like he was in a spy movie and couldn't divulge any top secret info for fear of legal action.......or hit men that would silence him for divulging the X-oil-files!
lol.gif
 
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