What 5W-30 oil brand are you using for the 6.6L gas?

[Antny]

On 8/24/2023 at 7:56 PM, nitro882 said:

I don’t have a 6.6l gas but if i did Amsoil would be what would go in it. It will be in my new Duramax for sure. 

I second this and it's so important with your particular engine... The L8T is a high performance engine and should be treated as such. The oil and gas mixture is critical in keeping piston blow-by at bay. I was burning oil in mine until I started using royal purple and puting 93Oct Shell with VPower Nitro in the tank. 3 oil changes later at 5,000 mile intervals and I am not burning any oil. The oil and the gas are modified to work together at detination, in order to create a molecular seal at the piston rings. This way, the oil is not getting into the combustion chamber and the fuel is not seeping past the rings into the crankcase. That particular oil also keeps the rings squeeky clean. This is a big deal if your putting a stressfull load on your engine. On another note, I run a Berryman Products 2611 Intake Valve and Combustion Chamber Cleaner, 16-Ounce Aerosol through the throttle body every 20,000. Just to keep the valves from gunking up.

[Epsilon Plus]

Mobil 1 from Costco. Dexos Gen 3. Have a catch can, filter mag and mag drain bolt. 

 

For all those treating this like a collectors F1 car, keep in mind fleets around the country are putting the cheapest crap they can find in these things, idling for untold hours and probably going way past the change intervals and their trucks are all going to be at auction with 250k+ miles on to it's next owner and run fine for another 100k.

 

TLDR, maybe save some money if you're overdoing it.

[Pryme]

On 2/1/2025 at 6:04 PM, Antny said:

I second this and it's so important with your particular engine... The L8T is a high performance engine and should be treated as such. The oil and gas mixture is critical in keeping piston blow-by at bay. I was burning oil in mine until I started using royal purple and puting 93Oct Shell with VPower Nitro in the tank. 3 oil changes later at 5,000 mile intervals and I am not burning any oil. The oil and the gas are modified to work together at detination, in order to create a molecular seal at the piston rings. This way, the oil is not getting into the combustion chamber and the fuel is not seeping past the rings into the crankcase. That particular oil also keeps the rings squeeky clean. This is a big deal if your putting a stressfull load on your engine. On another note, I run a Berryman Products 2611 Intake Valve and Combustion Chamber Cleaner, 16-Ounce Aerosol through the throttle body every 20,000. Just to keep the valves from gunking up.

How much oil were you burning before? Shell 93 is what I run in my bike but no way I’m spending that coin on a HD pickup. And RP oil is crazy expensive too. So you traded burning oil for burning cash. 

[Pryme]

1 hour ago, Epsilon Plus said:

Mobil 1 from Costco. Dexos Gen 3. Have a catch can, filter mag and mag drain bolt. 

 

For all those treating this like a collectors F1 car, keep in mind fleets around the country are putting the cheapest crap they can find in these things, idling for untold hours and probably going way past the change intervals and their trucks are all going to be at auction with 250k+ miles on to it's next owner and run fine for another 100k.

 

TLDR, maybe save some money if you're overdoing it.

I laughed at F1 collectors car. 

[Grumpy Bear]

On 8/22/2023 at 5:34 PM, customboss said:

I suspicion sliding wear with the 4 cyl to 2 cylinder mode at cruise is the culprit permanently damaging the additives that make crappy base oils work longer.

 

 

 

[Another JR]

I recently switched from Castrol full synthetic 5w-30 to Mobil One 5w-30 from Costco, primarily because of the ease and price buying it from Costco. I’m assuming that’s pretty much a step sideways in oil quality, but I’m curious about others’ opinions on that. I change at 3750 mile intervals because six months plus typically has gone by and so every other oil change lines up with a tire rotation. 
 

Edited February 21, 2025 by Another JR

[Black02Silverado]

14 hours ago, Another JR said:

I recently switched from Castrol full synthetic 5w-30 to Mobil One 5w-30 from Costco, primarily because of the ease and price buying it from Costco. I’m assuming that’s pretty much a step sideways in oil quality, but I’m curious about others’ opinions on that. I change at 3750 mile intervals because six months plus typically has gone by and so every other oil change lines up with a tire rotation. 
 

 

Changing it that often you will be just fine.

[Another JR]

47 minutes ago, Black02Silverado said:

 

Changing it that often you will be just fine.

Thank you for responding. I’m wondering if your response implies you see switching to Mobil One as a step down in oil quality or suitability. 

[Epsilon Plus]

Send a 3,750mi Dexos Gen 3 oil to Blackstone Labs and you'll get a report back that it's barely been used.

[Grumpy Bear]

On 2/21/2025 at 12:28 PM, Another JR said:

Thank you for responding. I’m wondering if your response implies you see switching to Mobil One as a step down in oil quality or suitability. 

 

That would depend on which of the various flavors of either you traded between. If they are equivalent DEXOS1Gen2/3/ILSAC GF6/ACEA C2 then they would be about the same.  

 

If that trade from one of the above was for a DEXOS2/ACEA C3/C4 you would have traded up. These have higher minimum HTHS viscosity values than the SAE *W30 values. More wear protection. Kind of important for a 3500 towing, right? Just say'n. 

 

30 minutes ago, Epsilon Plus said:

Send a 3,750mi Dexos Gen 3 oil to Blackstone Labs and you'll get a report back that it's barely been used.

 

Doesn't this statement say, and yes, I'm asking, not telling, that the only important parameter is milage in determining the useful life of oil? Or at minimum, that without exception, 3,750 miles will always shows "barely used". 

 

In addition, Blackstone does not test for 1.) Oxidation 2.) Nitration. It does not routinely include 3.) TAN. Which you kind of need to condemn on TBN. They use some rather crude tests for water, fuel & glycol. And quite concerning I see among the hundreds of test I looked at a surprising array of viscosity measurements outside SAE standards considered Okay. Oh and they mix test types for viscosity outside standards. SUS at 40C ??, Instead of cSt. ?

 

Now, all that said...What parameters is oil condemned on? And what agreement is there between labs on the exact levels for same. What basis in SCIENCE is there for those values? i.e. One lab condemns on a TBN of 1, another at 3, another at 50% or even 60% of the baseline. (which is often assumed instead of measured) Another at the TAN/TBN crossing point? Which method does the FACTS and SCIENCE support?

 

Hint, Regulation and Social Peer Pressure are currently overriding Facts and Truth.

 

Most labs don't measure Oxidation. Those that do, some condemn on 10 abs units over baseline. Some on 20-25 or even 30 units absent baseline. Oxidation is kind of important. 

 

How many routinely measure cleanliness? 

 

Just raising questions and offering observations.  

 

[OnTheReel]

Blackstone just tells people what they want to hear. They cater to the stooges on the BITOG forum who want to get 20k miles out of Walmart oil. The comments I’ve seen them make (not written by tribologists) typically fall somewhere between ill advised and downright absurd. 

[Jim71]

I use Kirkland brand and change every 5k.

[customboss]

On 2/25/2025 at 12:17 PM, OnTheReel said:

Blackstone just tells people what they want to hear. They cater to the stooges on the BITOG forum who want to get 20k miles out of Walmart oil. The comments I’ve seen them make (not written by tribologists) typically fall somewhere between ill advised and downright absurd. 

Another reason we need to get serious here and counter the BITOG BS.  My USN friend keeps getting thrown off the site because he is associated with ME. 

[customboss]

Smart and engaged folks here please join this Club to counter the drama queens online when it comes to fuels and lubes technology. 

 

 

Edited March 5, 2025 by customboss

[asilverblazer]

16 hours ago, customboss said:

Smart and engaged folks here please join this Club to ... when it comes to fuels and lubes technology. 

So some members here are well versed in oil... I struggle with to what end?

How many cars on the road today last over 200k miles using whatever brand, type (synthetic/non-synthetic/regular/blend) in the correct viscosity, at recommended change intervals? I'm thinking the generic time to change my oil, I'll go to where ever, or buy what's on sale types.

 

I just don't see this overwhelming collection of vehicles suffering catastrophic engine failures from using a 'bad' oil - that otherwise have a 'considerable' amount of life left in them.

 

The vehicle usually disintegrates around the engine. Body damage, faded paint, worn interiors, failing plastics, rust, crashes, etc. seem to condemn any vehicle before the 'I should have used a different oil' ever does. 

 

...NOT criticizing, just what's the interest here?