2018 Chevy Duramax L5P - 6,000 miles 19,500 miles total

[wwillson]

This is the second UOA from my Duramax L5P - 6,000 miles/150 hrs on oil - 19,500 miles total on truck. This is the first sample I'm a bit concerned with the fuel, wear metals, and oxidation. The truck is only used for pulling our travel trailer and get almost no short tripping.

 

[tundraotto]

That looks really good for the second oil change....what you are concerned about is because its still breaking in and shedding the contaminants in the oil!

 

[stockrex]

Fuel - I drain and fill just the oil 3k miles on average for the fuel issues related to the dpf, unfortunate but such is life. You have the better engine with the 9th injector, but looks like fuel is still whacky. I monitor my dpf cycle and on the hwy driving at 70, the dpf cycled after 98 miles, Can you do a dpf cycle count between oil changes? Cu - dmaxes are known for cu leaching from cooler lines, not sure if I would worry about it.

 

[wwillson]

Stockrex, I have found that the DPF regen interval is directly related to exhaust gas temperature. Pulling I will see a regen maybe every 1,500-2,000 miles, because the EGTs are hot and the soot gets burned out of the DPF as I drive. Not pulling the regen interval is about every 300 miles, because the EGTs are low and the DPF needs the regen heat to burn out the soot. The last time it regened before this oil change was unfortunately in stop and go traffic, so the process started and stopped several times. I wonder if that's where the fuel came from? Wayne

 

[stockrex]

Wayne, Yeap, chevy says it should not regen under x miles an hour, I told the dealer that mine regens in my driveway, there was one weekend I regen's the entire flippity weekend cuz I was making short trips with my kids, I think I went through 4 gallons of fuel. My new strategy is to make a run to cabelas when I start to regen if I am driving in town, just the right distance for dpf regen to complete. 1500 miles between regen, wow, get out, what fuel are you buying?

 

[JohnnyJohnson]

Originally Posted by stockrex

what fuel are you buying?

Yes I'm interested in this also. The fuel I use in my 2006 Duramax seems to make a lot of difference.

 

[A_Harman]

What flavor of Delvac 5w40 are you running? I'm wondering about what caused the high Oxidation reading. Did you run the truck hard during the OCI?

 

[wwillson]

Originally Posted by JohnnyJohnson

Originally Posted by stockrex

what fuel are you buying?

Yes I'm interested in this also. The fuel I use in my 2006 Duramax seems to make a lot of difference.

I run whatever fuel is available when we are on the road, we been from Utah to Florida and many states in between. Here is what I have been adding to the fuel https://betterdiesel.com/dpf-soot-filters/ I personally talked to Dr. Jane Gates, who is the formulator and owner of the company. She has an impressive bio in the science of diesel exhaust aftertreatment. After doing a bunch of reading on FBCs, my curiosity lead me to purchase some and try it out. We have about 6,000 miles of running with the FBC and I've found that the regens happen about 1/2 as often in mixed driving/pulling and when pulling constantly, I'm not sure I've seen a regen yet. Our stints on the road are usually about 1,000 miles to get where we are going, then a few hundred miles driving about the area before getting back on the road pulling the trailer to the next destination. The DFP will get loaded with the cool exhaust temps of using the truck to do sight seeing, then do a regen. If you start pulling soon after a regen, it won't regen the entire trip you're pulling. The furthest distance I've seen without a regen, while pulling, is 1,800 miles. From what I've seen the FBC works as advertised. I wasn't going to say anything until I got more miles, but I let the cat out of the bag.

 

[wwillson]

Originally Posted by A_Harman

What flavor of Delvac 5w40 are you running? I'm wondering about what caused the high Oxidation reading. Did you run the truck hard during the OCI?

It's the new CK-4 formulation. No, our trailer only weighs about 7,500 pounds and I drive like an old man. I've seen way too many fatal accidents caused by speed. The cruise is almost always set to 65 and I never pull the trailer faster than 70, even out west where the speed limit is 80. Our average fuel economy is 13.4 pulling, so the Duramax isn't working very hard.

 

[oakaro68]

Blackstone labs commented on how wear metals shouldn't be affected from initial wear in even at my 14.5k uoa sample I sent in. I was using Mobil Delvac 1 ESP 5w40 on this sample. This is an L5P as well.

 

[CarbonSteel]

A couple of thoughts: - The fuel dilution is from the regens, but I have to say that 1.7% is not bad at all. My Ford Powerstroke typically had 4-5% and that was only on a 5K run or so. - You should VOA the oil you are running to get a baseline on oxidation. I had considerably high oxidation (like yours) on a run of Delvac 1 ESP 5W-40 and was concerned. The VOA was not much lower so I ignored the reading from that point if it was "in the neighborhood". - The wear metals are from and engine still breaking in and the copper is likely from the oil cooler on the engine. I would wait a bit before being too concerned.

 

[wensteph]

Is the second UOA with using FBC the whole time? Fuel borne catalyst seems to be a coming thing. Infineum markets a product that looks to be marketed in the far east. https://www.infineum.com/en/products/fuels-portfolio/fuel-borne-catalysts/ Also several others I've not heard of. https://xenum.com/en/dpf-regeneration-additives/ and http://fpc1.com/index.php Goody. Another additive to try.

 

[CleverUserName]

The fuel is not from the Regens. Chevy uses a dedicated injector (sometimes called a 9th injector) mounted upstream of the DPF to spray fuel directly into the filter during a regen. They've used this technology since the LML was introduced in 2011. Ford doesn't use a 9th injector due to cost savings in manufacturing and relies on the primitive strategy of using main injection to supply fuel for Regen. That is the cause of YOUR fuel dilution and one of the main reasons why the 6.7 Powerstroke is technologically inferior to the Duramax. Someone recently posted a VOA of the new Delvac ESP on here. He doesn't need to have it analyzed.

Originally Posted by 2015_PSD

A couple of thoughts: - The fuel dilution is from the regens, but I have to say that 1.7% is not bad at all. My Ford Powerstroke typically had 4-5% and that was only on a 5K run or so. - You should VOA the oil you are running to get a baseline on oxidation. I had considerably high oxidation (like yours) on a run of Delvac 1 ESP 5W-40 and was concerned. The VOA was not much lower so I ignored the reading from that point if it was "in the neighborhood". - The wear metals are from and engine still breaking in and the copper is likely from the oil cooler on the engine. I would wait a bit before being too concerned.

 

[4WD]

Think Delvac Super 1300 is factory fill - might be a good Spring time fill

 

[A_Harman]

Originally Posted by wwillson

Originally Posted by A_Harman

What flavor of Delvac 5w40 are you running? I'm wondering about what caused the high Oxidation reading. Did you run the truck hard during the OCI?

It's the new CK-4 formulation. No, our trailer only weighs about 7,500 pounds and I drive like an old man. I've seen way too many fatal accidents caused by speed. The cruise is almost always set to 65 and I never pull the trailer faster than 70, even out west where the speed limit is 80. Our average fuel economy is 13.4 pulling, so the Duramax isn't working very hard.

Your usage is about the same as mine as an RV Transporter. My average trailer weight is 7000 pounds, and I typically cruise at 65, give or take a couple of mph. I could go faster, but fuel economy suffers, so I go slow to lower operating costs. They don't pay extra to get it there fast. It doesn't sound like the engine was run hard enough to oxidize the oil, so it must be that way from virgin.

 

[wwillson]

Originally Posted by wensteph

Is the second UOA with using FBC the whole time? Fuel borne catalyst seems to be a coming thing. Infineum markets a product that looks to be marketed in the far east. https://www.infineum.com/en/products/fuels-portfolio/fuel-borne-catalysts/ Also several others I've not heard of. https://xenum.com/en/dpf-regeneration-additives/ and http://fpc1.com/index.php Goody. Another additive to try.

Ah, light bulb moment, this particular FBC uses an iron compound, per Dr. Gates. I'll bet that's partially why I'm seeing higher Fe.

 

[wwillson]

Better Diesel FBC also claims better fuel economy, which I believe I may be seeing. However, I just don't have enough data yet to have a clear result and headwind vs tailwind can make the fuel economy results worthless. The fuel economy should be bench tested for accurate results.

 

[stockrex]

Wayne, FBC sound interesting, I need to research it bit more. When I looked at addys for DPF cycling too soon, I remember talking to these guys TDR-FL - Amalgamated, Inc, Not sure this product will work the same. How many hours do you have your engine? that might explain the fuel %, mine see a lot of idle time.

 

[wensteph]

stockrex, I've used TDR-FL with a TDI and working my way through a gallon now in the Duramax. What was your impression of your conversation with them? wwilson, my very limited knowledge makes me think the only mpg increase would come from fewer regens since what this stuff is supposed to do is lower the temperature soot gets burned to ash by 500 degree f causing less calls for a regen by the ECM.

 

[A_Harman]

Originally Posted by wwillson

Better Diesel FBC also claims better fuel economy, which I believe I may be seeing. However, I just don't have enough data yet to have a clear result and headwind vs tailwind can make the fuel economy results worthless. The fuel economy should be bench tested for accurate results.

Go to the Better Diesel website, and click on the link to download the brochure. It gives a case study of how they did controlled chassis dynamometer testing on a big rig. They report 14% improvement in fuel economy. It seems like the FBC is worth a try.