Good quality oil for fuel dilution?

[nicholas]

I never thought I would ask this- - -whats the best question, yet here we are.
Anyway - we do a lot of short trip driving in our 19 Santa Fe 2.0t. Even in the summer months we get noticable fuel dilution. The 5w-30 syn Seems to shear down very quickly. I notice this when I can hear the timing chain tensioner clacking on start up. It never does this at the start of the OCI - Usually starts to shear down 2.5k kms.

I have tried taking it on long drives -45+ min freeway drives. This does little to nothing for fuel smell and the thinning issue.

Anyway - - - does anyone know any good 5w-30's out there that can handle fuel a bit better?

I am thinking of trying a 5w-40 to see how far it will go. But for this I would like to know if there are any 30's out there?

Thanks

 

[JavierH19]

Any SP rated 40 grade you'll find on shelf. But pp euro l will also do since it's a thick 30 and mid saps.

 

[kschachn]

Is it fuel dilution or mechanical shear of the VII? You mention both.

Brand is more or less irrelevant with fuel dilution, the only way to help that with the oil is grade. You're diluting the oil with a low-viscosity fluid.

 

[LazyDog]

You can also change it more often in addition to the new oil choice.

 

[nicholas]

You can also change it more often in addition to the new oil choice.

Honestly - giving our driving profile - I think that will be something beneficial.

I plan to try a 5w-40 this month and monitor.

I think its the fuel in the oil perhaps contributing to the shear down of the 30 weight.

 

[PimTac]

What kind of fuel dilution numbers are you seeing on your oil analysis reports?

 

[RDY4WAR]

It's generally accepted that high amounts of viscosity index improver (VII) is undesirable when it comes to fuel dilution. Gasoline and diesel fuel alike can degrade the polymer, making it easier to break, and thus viscosity is lost at a greater rate than just the dilution itself. When VII content is minimized with a better quality (more resistant) polymer, or removed completely, the effects of fuel dilution become less prominent. This is the basis for oils like the High Performance Lubricants No VII series, to minimize the effects of fuel dilution.

 

[Rand]

for an off the shelf product pennzoil euro L is thick for a 30wt.

I'd go with m1 0w40 or a euro 5w40 with appropriate lspi mitigation specs.
Warranty may be a factor?

 

[ARCOgraphite]

Honestly - giving our driving profile - I think that will be something beneficial.

I plan to try a 5w-40 this month and monitor.

I think its the fuel in the oil perhaps contributing to the shear down of the 30 weight.

During months above 0degC/32degF, a 10W30. I am using QSFS 10W30seems to work OK on my diluting DI ford 2.0. and I can make it through to October.
I would stay away from 5W multigrades, unless they are ACEA A3 B4-16 high-HTHS lubricants.

You ARE going to have chain racket on startup on MOST vehicles, given the chains are near 2 metre in length and hydraulically tensioned

 

[Shel_B]

It's generally accepted that high amounts of viscosity index improver (VII) is undesirable when it comes to fuel dilution. Gasoline and diesel fuel alike can degrade the polymer, making it easier to break, and thus viscosity is lost at a greater rate than just the dilution itself. When VII content is minimized with a better quality (more resistant) polymer, or removed completely, the effects of fuel dilution become less prominent. This is the basis for oils like the High Performance Lubricants No VII series, to minimize the effects of fuel dilution.

Please clarify this statement. What do you mean by effects? The oil will still become diluted by fuel, will it not?

 

[RDY4WAR]

Please clarify this statement. What do you mean by effects? The oil will still become diluted by fuel, will it not?

Yes, but the viscosity loss from that fuel dilution will be less severe. It'll still lose viscosity from the dilution, there's no way around that, but when VII is involved, the degradation of the VII from that fuel causes the viscosity loss to be more severe. A good example was a recent UOA posted of HPL No VII 5W-30 with 4.5% fuel that was still in 30 grade range where most common shelf oils, with VII, would be down in 20 grade territory with that much fuel.

 

[Shel_B]

Yes, but the viscosity loss from that fuel dilution will be less severe. It'll still lose viscosity from the dilution, there's no way around that, but when VII is involved, the degradation of the VII from that fuel causes the viscosity loss to be more severe. A good example was a recent UOA posted of HPL No VII 5W-30 with 4.5% fuel that was still in 30 grade range where most common shelf oils, with VII, would be down in 20 grade territory with that much fuel.

That's good info for many folks. Another question: how is the lubricity of the oil affected by dilution regardless of the VII situation? I'd think the ability of the oil would suffer in some way.

 

[RDY4WAR]

Ester based anti-wear, friction reducer, and extreme pressure additives (such as ZDDP) can be impacted by fuel dilution and become less effective, particularly with ethanol. This is due to a transesterification process caused by the reaction of the ethanol with the acidic ester. In many cases though, you're not seeing ethanol in the oil in FTIR. Ethanol boils at 174°F so an engine at full operating temp, with >200°F oil and coolant, isn't going to have much issues with this. Engines that are short tripped will be more impacted.

 

[nicholas]

During months above 0degC/32degF, a 10W30. I am using QSFS 10W30seems to work OK on my diluting DI ford 2.0. and I can make it through to October.
I would stay away from 5W multigrades, unless they are ACEA A3 B4-16 high-HTHS lubricants.

You ARE going to have chain racket on startup on MOST vehicles, given the chains are near 2 metre in length and hydraulically tensioned

I understand this - -
However what is interesting is that even with a 5-30 I dont get any startup noises for a few thousand kms. Then Bingo they start.
My theory is that when the oil thins down to a 20 weight it drains much easier from the hydraulic tensioner and starts to cause this pressure building noise.

 

[nicholas]

Also- to note I use 15oz of lubegard Bio in my 5w-30 syn oil change- - - this has done nothing to extend the oils ability to stave off the eventual start up noise.

 

[kschachn]

It's generally accepted that high amounts of viscosity index improver (VII) is undesirable when it comes to fuel dilution. Gasoline and diesel fuel alike can degrade the polymer, making it easier to break, and thus viscosity is lost at a greater rate than just the dilution itself. When VII content is minimized with a better quality (more resistant) polymer, or removed completely, the effects of fuel dilution become less prominent. This is the basis for oils like the High Performance Lubricants No VII series, to minimize the effects of fuel dilution.

Is this for sure a permanent viscosity loss? Also is it impacted by the type and quality of the VII?

 

[RDY4WAR]

Is this for sure a permanent viscosity loss? Also is it impacted by the type and quality of the VII?

It's independent of the type of VII used. It's permanent and affects used oil more than fresh oil.

 

[kschachn]

It's independent of the type of VII used. It's permanent and affects used oil more than fresh oil.

Interesting, how can it be independent? Wouldn’t the morphology of the VII molecules be a factor? I’m not a polymer expert but I do recall HPL mentioning that star VII were more resistant. It’s easier to shear or cleave linear molecules than ones with cross links.

 

[RDY4WAR]

Interesting, how can it be independent? Wouldn’t the morphology of the VII molecules be a factor? I’m not a polymer expert but I do recall HPL mentioning that star VII were more resistant. It’s easier to shear or cleave linear molecules than ones with cross links.

Star polymers are more resistant to shear and thus the viscosity loss is less amplified, but it's still subject to the same degradation. There's also the fact that brands that pitch for star polymers also tend to use better quality base oils that need less VII and thus less effect.

 

[kschachn]

Star polymers are more resistant to shear and thus the viscosity loss is less amplified, but it's still subject to the same degradation. There's also the fact that brands that pitch for star polymers also tend to use better quality base oils that need less VII and thus less effect.

Okay thank you. It does tend to indicate to me that fuel dilution is not a good thing.