Valvoline AFS 5w-30 w/ 5k miles; GMC L8T 6.6L gas w/ 55k miles

[Tidmack]

Hi gang,

I have access to Fabick/Cat UOA kits at cost, so I thought I'd give one a try. This analysis was sent in with my 55,000 total miles, 5,000 mile interval change on my 2021 GMC 3500 L8T gas 6.6 L truck. The oil used is Valvoline Advanced Full Synthetic 5W30. This is a Dexos certified oil, as recommended by GM.

I took some time to read online about what each of these amounts mean in terms of wear, etc. After reviewing the numbers, I agree with the lab interpretation that all looks good at this time.

My question is regarding the Valvoline oil itself. Can anyone in the industry, or with knowledge of engine oil composition, let me know if the additive package Valvoline is using appears sufficient for my engine? Is this an oil I can continue to use with minimal wear on my engine? This is a truck I plan to keep as long as possible...I'm maintaining the rest of the truck at severe service intervals, and would like to drive it to 250k miles if I'm able.

I appreciate your help, thank you.

Jeff

 

[cptbarkey]

Vavoline is an excellent oil, and approved for your engine as you noted. It is actually very difficult for the layman to buy bad oil unless you take risks and like to buy no name off brand bottles of oil from a gas station. Check out PQIA's website for some examples.

Your UOA also looks excellent from a wear metals perspective. Thank you for sharing the data. UOA data on this forum isnt stored in a good format. You have to search and search and search to find a similar engine as yours to compare. Its just the nature of forum design, while not ideal for collecting data, its good for communicating.

Others will provide input, but in sum I think you and rest assured the engine will last you a long time.

 

[Tidmack]

I greatly appreciate your input, as well as the suggestion to check out PQIA's website. With a quick glance, I believe their site as the info I was looking for. Have a terrific weekend.

Jeff

 

[Jackson_Slugger]

Lots of Moly, always good...

 

[AZjeff]

Thanks for the report. I've got the same truck @ 23k miles running Quaker State FS 5W-30 on 5k OCIs. How is the rest of the truck at 55k?

 

[Snagglefoot]

The L8T is a great engine. Here is the recommendation from the owners manual. They specify a 5w30 Dexos 1 Gen 2. Gen 2 has now been superseded by Gen 3. So, if you want to stay with the GM recommendations you want a 5w30 Dexos 1 Gen 3, which by the way is an API SP motor oil.

It’s also notable that GM specs 5w30 for this engine and not 5w20 like in the 1500 trucks.

The predecessor to this engine was the 6.0. Mine has just over 250,000 miles, using 5w30 motor oil, with the latest API rating that was available since 2008, which included SM, SN and now SP. Your engine will most likely last for 250,000 miles and possibly more. Regarding the brand, I just look for the best deals. I also change oil every 5,000 miles which works out to about two changes a year for me right now. Good luck with engine.

 

[Tidmack]

Lots of Moly, always good...

Thank you. I did some additional reading, and completely agree.

 

[Tidmack]

Thanks for the report. I've got the same truck @ 23k miles running Quaker State FS 5W-30 on 5k OCIs. How is the rest of the truck at 55k?

So far so good. Even with sealing the holes in the top of the tailgate, I've gone through a couple tailgate switches. I also had a fuel pressure sensor in the tank go. Otherwise, she tows 7-8k lbs. pretty often and treats me well.

 

[Tidmack]

The L8T is a great engine. Here is the recommendation from the owners manual. They specify a 5w30 Dexos 1 Gen 2. Gen 2 has now been superseded by Gen 3. So, if you want to stay with the GM recommendations you want a 5w30 Dexos 1 Gen 3, which by the way is an API SP motor oil.

It’s also notable that GM specs 5w30 for this engine and not 5w20 like in the 1500 trucks.

The predecessor to this engine was the 6.0. Mine has just over 250,000 miles, using 5w30 motor oil, with the latest API rating that was available since 2008, which included SM, SN and now SP. Your engine will most likely last for 250,000 miles and possibly more. Regarding the brand, I just look for the best deals. I also change oil every 5,000 miles which works out to about two changes a year for me right now. Good luck with engine.

View attachment 200380

Thank you, I appreciate your input.

 

[Big_B]

Is the soot .2 or 2%?

 

[Tidmack]

Great question. I asked a technician at work about this, and I guess Cat's way of measuring soot involves a conversion chart. I was told 2 is ridiculously low.

 

[bjboertje]

They are probably used to seeing reports on diesels. Not going to be much soot in a n/a gas engine.