2021 GMC Yukon Denali Oil Burn

[DontTaseMeBro]

If I were in your shoes (collectively), I would stop using that piss water equivalent of 0w-20 oil and put in 5w-30. 0w-20 is a CAFE gimmick to eeeekkkkkk out a minute amount of mpg on EPA testing.

Run an oil designed for heavier use. 5w-30 has been the staple since around 2000, so why change now? The 6.6L gas motor specifies 5w-30 right on the oil cap. They share a lot of the same architecture, I'd go with what a commercial vehicle uses. Just my opinion.

What I wanna know is, how does 0W-20 wear compared to 5W-30 or 5W-40. Conventional wisdom would say it wears the same which isn’t a good thing. But ya, I’d still would wanna know.

 

[Antonm]

What I wanna know is, how does 0W-20 wear compared to 5W-30 or 5W-40. Conventional wisdom would say it wears the same which isn’t a good thing. But ya, I’d still would wanna know.

Conventional wisdom absolutely does not say it wears the same. Viscosity is key to preventing metal on metal wear.

The argument here between the oils would be does the 0w20 have enough viscosity,,,if it does,,, then there would be no benefit to thicker oils. And if the 0w20 did have enough viscosity, the downside of running a thicker oil would be a slight reduction in HP and fuel economy.

On the flip side, if the 0w20 doesn’t have enough viscosity to maintain the oil wedge between components, then the thicker oils would greatly reduce wear/ extend engine life.
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[15burban]

I've seen uoa's people have posted switching back and forth between 0w20 and 5-30. Same oci and the 0w20 show more wear. Does that mean that same motor will "wear out" 5k miles earlier running 0w20 or 50k? I don't know. If you trade in every few years does it really matter. We keep our vehicles for as long as possible so the only thing I ever put 0w20 in was the wife's last little mitsubishi suv that had a lifetime power train warranty.

 

[DontTaseMeBro]

Conventional wisdom absolutely does not say it wears the same. Viscosity is key to preventing metal on metal wear.

The argument here between the oils would be does the 0w20 have enough viscosity,,,if it does,,, then there would be no benefit to thicker oils. And if the 0w20 did have enough viscosity, the downside of running a thicker oil would be a slight reduction in HP and fuel economy.

On the flip side, if the 0w20 doesn’t have enough viscosity to maintain the oil wedge between components, then the thicker oils would greatly reduce wear/ extend engine life.
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What I meant by “wears the same” is the time it takes(engine hours) to wear down from its 20 viscosity. There’s a post in one of the other threads where it’s states that after 3000 miles driven, 5w-40 was barely at that viscosity still.

So to restate what I was saying, would 0w-20 still have a viscosity of 20 after 3000 miles?

 

[Antonm]

What I meant by “wears the same” is the time it takes(engine hours) to wear down from its 20 viscosity. There’s a post in one of the other threads where it’s states that after 3000 miles driven, 5w-40 was barely at that viscosity still.

So to restate what I was saying, would 0w-20 still have a viscosity of 20 after 3000 miles?

Ah, you were talking about shear reducing viscosity of oil over time.
Of course both oils will shear as they're used, but they probably won't shear at the same rate. Generally the higher the spread between the winter number (the "0" in 0W40) and normal viscosity number (the "40" in 0W40) means the oil will shear quicker (i.e a 0W40 will shear quicker than a 15W40) .
This used to be a big concern for the diesel guys that like to really extend oil change intervals, but it's been talked about less in recent years so maybe it's not as big a deal as it once was.
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[DontTaseMeBro]

Ah, you were talking about shear reducing viscosity of oil over time.
Of course both oils will shear as they're used, but they probably won't shear at the same rate. Generally the higher the spread between the winter number (the "0" in 0W40) and normal viscosity number (the "40" in 0W40) means the oil will shear quicker (i.e a 0W40 will shear quicker than a 15W40) .
This used to be a big concern for the diesel guys that like to really extend oil change intervals, but it's been talked about less in recent years so maybe it's not as big a deal as it once was.
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That’s exactly what I meant, thank you! So yes, would be interesting to see how 0W-20 shears in the real world compared to the other viscosity oils.

 

[geneblakeney]

I have a 21 Yukon. I had this same issue. Low oil warning. I checked dipstik. It was very low. It persisted. Finally took it to the shop at 101k miles. OUT of warranty. They said the gaskets on the pistons deteriorate and that causes oil to leak in there and burn up. Only fix is to rebuild engine or replace. They said it also has a little bit of oil leak. No one said anything about type of oil used. They said that i just need to change oil every 4-5k miles. Ignore what computer says. It will extend the oil life based on highway miles. All that being said we will probably buy a new one soon.

 

[NoYukonYet_1Jeep]

So, I know that hardly anyone does this anymore, but you really should pull the dipstick and check the oil level at every fill up.

The “oil life monitor” which is the % oil life sensor in the instrument cluster only tells you the computer calculated life remaining in the oil. It’s based on a ton of research by engineers at GM, and algorithmically counts down from 100% based on the number of engine revolutions, with some de-rating for engine temperature, number of cold starts, driving conditions, etc. It has shown to be pretty accurate by used oil analysis performed by many.

But, that piece of tech assumes you start with a full crankcase of fresh oil when reset to 100%, and that you keep the crankcase properly filled with oil. The best way to do this is following the oil check procedure in the owners manual. Basically: pull the dipstick occasionally and check.

In every vehicle I’ve ever owned, I check it the day I buy it, then at every fill up, and after every oil change. I’ve had a couple of my vehicles overfilled or under filled by the service tech..and corrected on the spot. Checking at every fill up gives you:
- Confidence you are not low on oil
- Indication of how your specific engine is behaving
- And over time, if you know you consume 0.5qt every 5000 miles, also an indication when something is changing, if all of a sudden it’s 1qt every 2500

TLDR: don’t be a dipstick, use the dipstick!

Wanted to say this is the simplest, best, most straightforward advice I’ve read on this forum, hands down. I’ve had a technological wake up call - where I thought a 2023-24-25 model year vehicle no longer required a physical dip stick check. I’m no stranger to hands on - lots of things I tinker with, but caught a fun little reminder pre-800 mile road trip when the night before my low oil warning came on. Popped the dip stick, bone dry. ‍‍. Added 1.5 quarts. (34% oil life) I’m in so cal so it’s warm and I put a decent bit of mileage on her, not to mention round trips to Vegas more than I care to admit. Can mark my words I’ll be pulling that dipstick on the regular going forward. Cheers to you WallEyeMikeIII. Great reminder that even with all the tech we have, still gotta pop that hood to keep your things in order. Been doing oil changes at local Chevy dealer, and I’m going to give them some words next time - the service girl taking appts actually said they don’t recommend oil changes “before it gets below 20%”. Would’ve saved me here bc I’ll usually play it safe and change the oil around 35-40%.

TLDR - we burning oil. 2023 Yukon Denali 6.2L, 24k miles . 35% oil life remaining, low oil light, dry dipstick

 

[Antonm]

The 0W-20 oil also plays a part in the oil consumption.

That thin *** oil gets past piston rings and gets entrained in positive crankcase ventilation gas flow way easier than real oil.

Running a thicker oil helps slow down the consumption issues these engines have ( won’t eliminate it, but it will slow it down).

I put an oil catch can on our 6.2 Tahoe at about 500 miles. I get WAY more oil caught in it when running 0W20 oil compared to when running 0W40 oil for the same mileage.

And before anyone gets all preachy about how 0W40 is the wrong oil, GM specs 0W40 oil in the corvette 6.2. Yes there are differences between the truck and the corvette 6.2 but the bottom end rotating assembly (you know, the parts the oil touch) is the same. Mobil 1 even makes an 0W40 oil that carries the appropriate GM dexos rating.
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