6.7 PSD HPL 5w40 9800 miles

[mattd]

Here is my 10K sample. It has been in the sump since October of 2021. Fuel is stupid this go around. Likely from the short winter driving I have been doing. However I did do a lot of towing over the summer and fall even into November. When I leave in the morning I put the truck on fast idle for about 5 minutes before I go when it’s very cold. I usually am able to drive it until it reaches 190* EOT but it’s not maintained long there before shutdown. They suggest a lube change, but viscosity is still at 12.9. I would think it would be much less with over 7% fuel. Other than that I don’t really don’t have a problem with the wear metals. The silicon is STILL leaching from the reseal about 12,000 miles ago.

@High Performance Lubricants would you suggest a lube change?

 

[fantastic]

Sounds like you're thinking it just doesn't have enough time to burn off. I could recommend doing like a 30 mile trip before doing a UOA again?

I think wasn't it International that started fuel condemnation at 10%.

I just don't see any real wear going on even with that 7%. Oxidation still seems inline too.

 

[High Performance Lubricants]

Past analysis would indicate the wear rates will be stable until you pass 15%. I would run it further if it were mine.

 

[mattd]

I know the photo is not the clearest but to highlight: Iron 27, Chromium 1, Aluminum 3, copper 2, silicon 46, fuel 7.6%, visc. 12.9, soot .4%, tbn 6.42.

 

[RDY4WAR]

While there is a good bit of fuel, the UOA doesn't show any harm from it. The oxidation is stable, TBN is still >6, and KV100 is still a 40 grade. I see no reason it couldn't be run further.

 

[mattd]

While I agree with Dave and above regarding wear is well in check despite the fuel, I do have some concerns with leaving that much fuel in the crankcase for extended periods of time slowly degrading the seals and gaskets on the engine. I have some thinking to do. I may resample
In 2500 miles or so and recheck the fuel.

 

[SubieRubyRoo]

While I agree with Dave and above regarding wear is well in check despite the fuel, I do have some concerns with leaving that much fuel in the crankcase for extended periods of time slowly degrading the seals and gaskets on the engine. I have some thinking to do. I may resample
In 2500 miles or so and recheck the fuel.

Try to give it a good long highway run either in hills or into a stiff headwind for a couple hours. I don’t really see how fuel would degrade seals or gaskets the way you assume, but I’m also not a materials engineer. I’m on board with your 2.5k resample though. HPL is impressive, 2.7ppm Fe and 0.3ppm Al… very low!

 

[mattd]

Try to give it a good long highway run either in hills or into a stiff headwind for a couple hours. I don’t really see how fuel would degrade seals or gaskets the way you assume, but I’m also not a materials engineer. I’m on board with your 2.5k resample though. HPL is impressive, 2.7ppm Fe and 0.3ppm Al… very low!

Diesel fuel swells rubber and will also dissolve silicone. It does need a good highway run, I’ll try to have to set some time aside.

 

[mattd]

I should also note this sample had 364 hours on it. If a mod could add that to the title I would appreciate it, thank you.

 

[wwillson]

It does need a good highway run, I’ll try to have to set some time aside.

Hook it to my trailer and pull it into the wind...

 

[RDY4WAR]

Fuel dilution with a diesel is different from a gas engine. Diesel's initial boiling point (IBP) is ~150°C (~300°F), 50% evaporated @ ~250°C (~480°F) so a long highway run is unlikely to remove much of the fuel from the sump. You'll get localized evaporation around the pistons/rings but unlikely enough to counter the fuel being added. What a highway run will do is likely allow more of the diesel (%) to evaporate and burn in the cylinder rather than seeping into the crankcase. The fuel dilution percentage gain rate will likely be lower but still contributing. The fuel dilution will likely remain the same at best.

Gasoline has an IBP of ~40°C (~100°F), 50% @ ~100°C (~210°F), and is ~80% evaporated at 300°F when diesel is just starting to evaporate. A long run on the highway, with the oil temps in the 210-250°F range, can remove a good bit of gasoline from the sump of a gas engine. However, it's unlikely to see much dissipation in a diesel engine.

I would sample again at 12,500 - 13,500 miles to check for fuel dilution and KV100, keeping in mind a condemnation limit of 10% fuel. Changing the oil now and continuing with 10,000 mile OCIs would be good as well if you want to have headroom. I would continue using HPL oil henceforth since despite the high dilution, it's still in grade, and still has a strong TBN. A lot of lesser oils, that just meet the spec, would be diluted well into the 30 grade range at this point.

 

[mattd]

Fuel dilution with a diesel is different from a gas engine. Diesel's initial boiling point (IBP) is ~150°C (~300°F), 50% evaporated @ ~250°C (~480°F) so a long highway run is unlikely to remove much of the fuel from the sump. You'll get localized evaporation around the pistons/rings but unlikely enough to counter the fuel being added. What a highway run will do is likely allow more of the diesel (%) to evaporate and burn in the cylinder rather than seeping into the crankcase. The fuel dilution percentage gain rate will likely be lower but still contributing. The fuel dilution will likely remain the same at best.

Gasoline has an IBP of ~40°C (~100°F), 50% @ ~100°C (~210°F), and is ~80% evaporated at 300°F when diesel is just starting to evaporate. A long run on the highway, with the oil temps in the 210-250°F range, can remove a good bit of gasoline from the sump of a gas engine. However, it's unlikely to see much dissipation in a diesel engine.

I would sample again at 12,500 - 13,500 miles to check for fuel dilution and KV100, keeping in mind a condemnation limit of 10% fuel. Changing the oil now and continuing with 10,000 mile OCIs would be good as well if you want to have headroom. I would continue using HPL oil henceforth since despite the high dilution, it's still in grade, and still has a strong TBN. A lot of lesser oils, that just meet the spec, would be diluted well into the 30 grade range at this point.

You are correct about diesel mixing much easier than gas about burning off. One of my big reasons about leaning toward changing the lube. The fuel in there now won’t burn off no matter how long the drive is.

 

[fantastic]

Fuel dilution with a diesel is different from a gas engine. Diesel's initial boiling point (IBP) is ~150°C (~300°F), 50% evaporated @ ~250°C (~480°F) so a long highway run is unlikely to remove much of the fuel from the sump. You'll get localized evaporation around the pistons/rings but unlikely enough to counter the fuel being added. What a highway run will do is likely allow more of the diesel (%) to evaporate and burn in the cylinder rather than seeping into the crankcase. The fuel dilution percentage gain rate will likely be lower but still contributing. The fuel dilution will likely remain the same at best.

Gasoline has an IBP of ~40°C (~100°F), 50% @ ~100°C (~210°F), and is ~80% evaporated at 300°F when diesel is just starting to evaporate. A long run on the highway, with the oil temps in the 210-250°F range, can remove a good bit of gasoline from the sump of a gas engine. However, it's unlikely to see much dissipation in a diesel engine.

The engineering of a diesel engine takes "Less Flammable diesel" into account already. It's a much higher compression ratio than gasoline for starters. I believe a long or longer run, 30-80 Miles or more, on a hot day could burn the fuel in the oil. It may take a longer highway run than what I posted but it should burn up some but potentially not all of it. Shorter runs with idling are the exception.

At any rate.. OP can change oil & duplicate the mileage run here then re-test. If diesel fuel still 7%+ & if they feel more comfortable changing it then there is no harm done.

These are just my thoughts & the only real way to find out would be to test with UOA immediately after pulling into the driveway. Taking care, with gloves, not to burn the hands though.

 

[The Critic]

At what mileage did the OLM request an oil change? That is probably a good baseline on what the OEM deems to be acceptable, at least from a fuel dilution standpoint.

 

[mattd]

At what mileage did the OLM request an oil change? That is probably a good baseline on what the OEM deems to be acceptable, at least from a fuel dilution standpoint.

IIRC it timed out at the one year mark in October. Maybe a little over 8000 miles.

 

[mattd]

I want to clarify too this truck never sits at low idle. If it had to be stationary and running at all for any length of time it goes on fast idle.

 

[Pedro I]

As I understand the criteria for maximum reasonable fuel is 4-5% according to many labs.
At 8% fuel it is well above what is considered a safe %.
Driving with more fuel can cause wear on copper parts and in many tests with the presence of fuel copper and iron are elevated.
Actually to see if more damage is caused than usual we will have to do an analysis with more miles and see if the wear rises proportionally or rises sharply.
I would like to understand the reason why oil change is not condemned here immediately with these fuel values?

 

[fantastic]

I would like to understand the reason why oil change is not condemned here immediately with these fuel values?

Because the fuel delusion doesn't seem to be causing any abnormal wear for this mileage duration.

 

[Pedro I]

@fantastic

Indeed, the wear is reasonable for the moment, we have a 5w40 lubricant that can still be called 5w40 according to the viscosity of the analysis, we have low wear values so carte blanche to continue using the lubricant for a longer period of time.

My question was a little more focused on whether there is already something official from an additive or oil manufacturer or studies that say that the condemnation of the oil change should be done after 10% of diesel fuel because they found additives that can handle such amount of fuel without damage.

Just trying to keep up to date with new developments in lubrication because I too am struggling with fuel dilution in two TDI euro 6.

To date I have not found any oil manufacturer that claims their oils can handle more than 4-5% diesel fuel and apparently the labs themselves have this standard. I guess the damage does not only happen in the metal and could go further affecting seals and oil seals.

I am really excited to see such an amount of fuel and see no condemnation of change.

 

[fantastic]

@fantastic

Indeed, the wear is reasonable for the moment, we have a 5w40 lubricant that can still be called 5w40 according to the viscosity of the analysis, we have low wear values so carte blanche to continue using the lubricant for a longer period of time.

My question was a little more focused on whether there is already something official from an additive or oil manufacturer or studies that say that the condemnation of the oil change should be done after 10% of diesel fuel because they found additives that can handle such amount of fuel without damage.

Just trying to keep up to date with new developments in lubrication because I too am struggling with fuel dilution in two TDI euro 6.

To date I have not found any oil manufacturer that claims their oils can handle more than 4-5% diesel fuel and apparently the labs themselves have this standard. I guess the damage does not only happen in the metal and could go further affecting seals and oil seals.

I am really excited to see such an amount of fuel and see no condemnation of change.

I've not saw anything official with oil manufacturers. Usually it's the engine manufacturer that sets the limits. Engine oil is the outcome of the vehicles we drive over time and it's constantly changing. Today's oils are definitely robust for the current fuel delusion issues we're seeing as we see in this report.
Again to get specific fuel condemnation limits you'll need to get that from the engine builders. However some will never say.