What oil to use?

[OhighoTB]

Good news for me I guess! Cylinders never shut off on my engine. Always trying to keep it 6-7 MPG. Premium gas is cheap now!

These engines don't show them shutting down, but they do. Just bought mine and they said it didn't. But it does, it can be 1,3,5 cylinders running it does calculations real fast. They say driver doesn't feel it. I do tho, I pay close attention to my vehicles. Thinking about getting pulsar.

 

[Baz]

These engines don't show them shutting down, but they do. Just bought mine and they said it didn't. But it does, it can be 1,3,5 cylinders running it does calculations real fast. They say driver doesn't feel it. I do tho, I pay close attention to my vehicles. Thinking about getting pulsar.

You won’t regret it… it made a world of difference for my 2020 6.2L.

 

[Jmzvet]

Though I don't use 5w30, 5w-30 wont hurt your engine. The lighter viscosity is designated primarily for EPA numbers. Your gas mileage will suffer ever so slightly using a thicker oil, but your engine will be fine.

I run the 0/20 but 5/30 definitely won't ruin your engine. Especially in warmer climates.
I get 20 quarts of Costco 0/20 full synthetic for $80 shipped to my door. It exceeds all requirements. I run it in all 3 of my vehicles which spec 0/20 synthetic

 

[Transient]

Because the motor has the same clearances as the 3.6L which calls for 5W30. A lot of these trucks up here are work trucks and they idle all day to stay warm in the cold during the winter out on site.

Id recommend following the manual as well, but it's not hard to engage in critical thinking skills.

Critical thinking skills dictate when one is not an expert, one should follow what the experts say. I'm not an engineer, and I doubt the dealership employs an engineer. Critical thinking requires knowing when to follow what the experts say otherwise lawyers get involved, and they love to listen to the experts. I don't pretend to be an expert, but I do follow what the experts say. Bad things happen when I don't. I already paid $2,500 USD just to purchase the 6.2 over the 5.3. I'm of the mindset that I don't wish to piss away that money. I've also dealt with an engine failure on a 5.3 in a 2007 Tahoe that ran 5w-30. If GM has changed things up, it's because an expert they employ told them too. GM has been dealing with engine failures associated with cylinder deactivation for over a decade. They've had plenty of time to research whether or not oil weight was a factor, and how best they can mitigate failure from repeating (and possibly reduce the odds of a class action lawsuit from being filed against them). They have even submitted their vehicles to cold weather testing for the last 50 years at their cold weather testing facility.

https://gmauthority.com/blog/gm/gm-facilities/gm-canada-facilities/gm-cold-weather-development-center-kapuskasing-ontario-canada/#:~:text=The%20GM%20Cold%20Weather%20Development,in%20Kapuskasing%2C%20Ontario%2C%20Canada.

 

[40feralhogs]

Man I'm agreeing with you to follow the manual I'm just saying 5w30 is obviously also fine.

 

[The Raven]

0w20 is in fact required because of the DFM system. The VLOM that controls cylinder shutdown is calibrated based on 0w20 oil viscosity, and if you deviate too far from the viscosity the system is designed for, it's theoretically possible that the VLOM could actuate the lifters outside of a commanded shutdown, and that would be disastrous for the motor. Now, 5w30 is only slightly different than 0w20 so one could argue that that tiny little difference couldn't possibly be a problem, and that person could be right. But none of us are the designers of this system so it seems pretty unintelligent to make that call ourselves. I recommend just following the factory spec. Furthermore, if you experienced the dreaded lifter failure, and GM somehow determined that you were running 5w30, it's quite likely that you would be on your own. Doesn't seem worth it to me. 0w20 is no more expensive nor difficult to find, so just use that.

 

[Gangly]

0w20 is in fact required because of the DFM system. The VLOM that controls cylinder shutdown is calibrated based on 0w20 oil viscosity, and if you deviate too far from the viscosity the system is designed for, it's theoretically possible that the VLOM could actuate the lifters outside of a commanded shutdown, and that would be disastrous for the motor. Now, 5w30 is only slightly different than 0w20 so one could argue that that tiny little difference couldn't possibly be a problem, and that person could be right. But none of us are the designers of this system so it seems pretty unintelligent to make that call ourselves. I recommend just following the factory spec. Furthermore, if you experienced the dreaded lifter failure, and GM somehow determined that you were running 5w30, it's quite likely that you would be on your own. Doesn't seem worth it to me. 0w20 is no more expensive nor difficult to find, so just use that.

Incorrect, DFM does not use VLOM or LOMA(Lifter Oil Manifold System), only the legacy AFM systems do. DFM utilizes OCV's, or Oil Controlled Valves that provide faster response times than LOMA and are required for DFM (on L84 and L87). OCVs are also used on L82 for AFM.

 

[The Raven]

Incorrect, DFM does not use VLOM or LOMA(Lifter Oil Manifold System), only the legacy AFM systems do. DFM utilizes OCV's, or Oil Controlled Valves that provide faster response times than LOMA and are required for DFM (on L84 and L87). OCVs are also used on L82 for AFM.

Ugh. I should have known there'd be a Mr. Technical stopping by to nitpick. Thanks I guess.

 

[Gangly]

Ugh. I should have known there'd be a Mr. Technical stopping by to nitpick. Thanks I guess.

Nitpick, or correct false information?
It's ok to be wrong, we are all wrong on occasion, the problems arise when we don't learn from mistakes.

There was no mean or ill intent, I am usually the one who is mistaken 90% of the time and have to be corrected.

 

[40feralhogs]

Honestly it's pretty suspicious that a bunch of manufacturers all switched to lighter oils right after the EPA regs tightened up. Specially when considered most are engines that are based on 20-30 year old designs that all ran heavier oil.

I'm not smarter than the engineers who designed the engine, but ask yourself what came first in this situation the chicken or the egg?

I strongly suspect this was done to meet a regulatory standard and not because it's actually a better choice or has some sort of advantage in the updated design.

I will end this post with reiterating though: I'm not smarter than the engineers and I do believe you should follow the manual. It's just logical in case something does go wrong and you can maintain your warranty by following their specifcations.

 

[The Raven]

Nitpick, or correct false information?
It's ok to be wrong, we are all wrong on occasion, the problems arise when we don't learn from mistakes.

There was no mean or ill intent, I am usually the one who is mistaken 90% of the time and have to be corrected.

Ok kid no need to lecture. The point was that your "correction" was irrelevant to the point of my comment. THAT is a nitpick. It doesn't matter what the device technically is. It matters that it cares what oil viscosity it sees.

Sometimes it's not important that every little detail is spot on, as long as the overall point is. Otherwise, you end up looking like that nerd in class who's hand always flies up every time the teacher asks a question.

Honestly it's pretty suspicious that a bunch of manufacturers all switched to lighter oils right after the EPA regs tightened up. Specially when considered most are engines that are based on 20-30 year old designs that all ran heavier oil.

I'm not smarter than the engineers who designed the engine, but ask yourself what came first in this situation the chicken or the egg?

I strongly suspect this was done to meet a regulatory standard and not because it's actually a better choice or has some sort of advantage in the updated design.

You may be right...problem is, we don't know. Furthermore, there is no cost or convenience penalty to running 0w-20 so again, why not just do that?

 

[40feralhogs]

You may be right...problem is, we don't know. Furthermore, there is no cost or convenience penalty to running 0w-20 so again, why not just do that?

Did you not read all of my post where I literally said this or were you to busy crying about being wrong?

 

[Transient]

Since we're getting hung up on 5w30 versus 0w20 and have now dove into the EPA, I feel like exploring this.

Over 20 years ago Japanese imports started using 0w20 in what were dubbed tight tolerance high compression engines. These same little 4 cylinder engines we being awarded LEV and ULEV certifications. They were also achieving high mpg numbers at the time. Exploring the argument that the 5.3 and 6.2 were built to run on 5w30 and 0w20 isn't much different, and the EPA forcing tighter regulations for emissions and increased mpg, is the thickness of the 2 oils really enough to increase mpg and reduced emissions while providing satisficing protection to the engine? The way the wheels in my head are turning, the change in oil weight may have been to satisfy the EPA and GM engineers decided this was one way to do it because the thinner oil would produce less of a drag on moving engine parts thus making it more efficient?

I really don't know if my questions are making sense. I'm trying to wrap my head around how I ask those questions. That's why the sentences may seem poorly structured.

 

[The Raven]

Did you not read all of my post where I literally said this or were you to busy crying about being wrong?

Another one?! I'm sorry, I guess I must have stepped into the gifted classroom. I'll just see myself out now.

 

[Gangly]

Ok kid no need to lecture. The point was that your "correction" was irrelevant to the point of my comment. THAT is a nitpick. It doesn't matter what the device technically is. It matters that it cares what oil viscosity it sees.

Sometimes it's not important that every little detail is spot on, as long as the overall point is. Otherwise, you end up looking like that nerd in class who's hand always flies up every time the teacher asks a question.




You may be right...problem is, we don't know. Furthermore, there is no cost or convenience penalty to running 0w-20 so again, why not just do that?

Panties in a twist? Lame attempts at insults are for children who have lost arguments and have nothing left to throw but insults.

The point is that my "correction" was completely relevant to your comment as you said the VLOM was designed for 0W-20. The newer 5.3's and 6.2's in the TB's dont have VLOM, so your statement is completely, and utterly irrelevant to our trucks. That's not a nit pick, that's a correction of bad information.

Maybe if you tried to act like the nerd in the class you would understand how bad information is infinitely worse than no information, and if you cant provide accurate information, its often times best to sit back and listen.

Hopefully the OP gets some accurate information throughout this topics progression.