Oil viscosity recommendation

[06 Yukon XL]

So my 2020 YuKon XL with the 5.3 engine it says to use 0W-20 oil and in my former 2010 Yukon XL with the 5.3 engine. I ran 5W-30, and engine was still running smooth at 292,000km. What are you folks running in your 5.3 liter engines? Can I run 5W-30 in this one also, which is what I prefer to do.

 

[fondupot]

Sounds like you already know what you want. 5W30 will be fine. the 0W20 is recommended by the manufacturer to maximize fuel mileage. In reality the difference between the two is not that much.

 

[swathdiver]

0W20 has less shear protection than 5W30 but is plenty of protection for the 5.3 engine. Having said that, I too would run 5W30 if my intention was to take the engine over 200K miles.

 

[Marky Dissod]

Can I run 5W30 in this one also ... ?

If the motor oil is good enough for the 6.6L L8T, it's good enough for your engine.

 

[blanchard7684]

So my 2020 YuKon XL with the 5.3 engine it says to use 0W-20 oil and in my former 2010 Yukon XL with the 5.3 engine. I ran 5W-30, and engine was still running smooth at 292,000km. What are you folks running in your 5.3 liter engines? Can I run 5W-30 in this one also, which is what I prefer to do.

I have a '24 5.3 Suburban and use 5w30 preferentially. However I wouldn't lose sleep if I was in a bind and had to do an oil change and all I could find was a Dexos spec 0W20. I haven't seen a loss of fuel mileage with 5w30 either.

0W20 gives a slight margin of safety above max load capacity for engine bearings in a worst case scenario of low rpm and high loads. 5w30 gives a good margin of safety meaning the oil can dilute a bit and still maintain film strength at worst case conditions. This is calculations based on Sommerfeld number and Stribeck curve.

The other thing going for the 5.3 in this platform is the 10 spd is configured to keep rpms a bit higher (than 6.2) on a highway cruise which unloads the bearings.

The situation is not the same with 6.2 engine.

 

[swathdiver]

0W20 gives a slight margin of safety above max load capacity for engine bearings in a worst case scenario of low rpm and high loads. 5w30 gives a good margin of safety meaning the oil can dilute a bit and still maintain film strength at worst case conditions.

Exactly, this is what I was trying to get across to our Russian friend in the other post. My wore out 5W30 has more viscosity (D445) in it than new 0W20.

 

[Miami-Dade]

@06 Yukon XL Moved you here from 2021+section.

My 2016 5.3 Tahoe has been using 0w20 for the past 197K miles. Change out every 5K miles. Use either Mobil 1 EP or AC Delco.

 

[vcode]

I have a '24 5.3 Suburban and use 5w30 preferentially. However I wouldn't lose sleep if I was in a bind and had to do an oil change and all I could find was a Dexos spec 0W20. I haven't seen a loss of fuel mileage with 5w30 either.

0W20 gives a slight margin of safety above max load capacity for engine bearings in a worst case scenario of low rpm and high loads. 5w30 gives a good margin of safety meaning the oil can dilute a bit and still maintain film strength at worst case conditions. This is calculations based on Sommerfeld number and Stribeck curve.

The other thing going for the 5.3 in this platform is the 10 spd is configured to keep rpms a bit higher (than 6.2) on a highway cruise which unloads the bearings.

The situation is not the same with 6.2 engine.

5.3L should still be using the 6 speed in 2020.

 

[vcode]

@06 Yukon XL Moved you here from 2021+section.

My 2016 5.3 Tahoe has been using 0w20 for the past 197K miles. Change out every 5K miles. Use either Mobil 1 EP or AC Delco.

AFM/DFM disabled or still operating?

 

[Miami-Dade]

AFM/DFM disabled or still operating?

Still operating.

 

[2017sltXL]

Exactly, this is what I was trying to get across to our Russian friend in the other post. My wore out 5W30 has more viscosity (D445) in it than new 0W20.

Exactly this. 0W20 is not that weight after it's sheared down over time, and these DI engines are already prone to some fuel dilution. I run Mobil 1 5W30 ESP in mine, and changed the fill cap to the same weight.

 

[vcode]

Lets be honest, most people believe that GM has the engineering expertise to know what oil is correct for their engines, and there are others who don't. It's the same story for virtually every manufacturer out there and is unlikely to change.

 

[Marky Dissod]

... most people believe that GM has the engineering expertise to know what oil is correct for their engines ...

Yes, AND THEN CAFE MpG test scores skew the desired results.
This is why the very low-volume 'vettes avoid 0W20, the 6.6L L8T specs 5W30,
and the higher-volume-selling vehicles that have a much larger effect on an automaker's CAFE MpG scores spec 0W20.

In any scenario where 0W20 may be 'good enough', 0W30 / 5W30 is better, so sayeth the Stribeck curve - unless the goal is to eke out that last MpG.
If CAFE MpG test scores stopped leaning on the requirements, 0W30 & 5W30 would be de rigeur.

 

[Jake707]

With 5W30 being better protection over the 0W20 from the factory, why stop there? Why doesn't anyone suggest a 10W30 or 10W40? Why not a 20W50 even haha

 

[swathdiver]

With 5W30 being better protection over the 0W20 from the factory, why stop there? Why doesn't anyone suggest a 10W30 or 10W40? Why not a 20W50 even haha

Because those oils are too "thick" to flow through the engine and do the work asked of it properly. Oil is used to do work and not just lubricate and cool these days. They use it to collapse the pins on the AFM lifters and to work the VVT system for example.

 

[Marky Dissod]

With 5W30 being better protection over the 0W20 from the factory, why stop there?
Why doesn't anyone suggest a 10W30 or 10W40? Why not a 20W50 even?

10W30, 10W40, & 20W50 would provide worse protection at cold start-up than 0W30 or 5W30.
10W40 & 20W50 have not been suggested because our engine assembly clearances, as well as most of our typical use cases,
neither warrant using those grades, nor would using 10W40 or 20W50 provide any additional protection.
(Although I could see 10W40 potentially being useful during edge cases involving towing or racing?)

 

[PPV_2018]

Exactly this. 0W20 is not that weight after it's sheared down over time, and these DI engines are already prone to some fuel dilution. I run Mobil 1 5W30 ESP in mine, and changed the fill cap to the same weight.

Does anybody actually know how long it takes for fuel dilution + contaminants to break down the oil to the point where it is no longer providing adequate protection?


We hear a lot about fuel dilution and wear breaking down the ow20 oil to basically nothing, but I never hear concrete numbers as to how long 0w20 would be considered good to use from the hardline 5w30 advocates. I mean surely it doesn’t break down within 3k miles?

Where I’m going with this is If OCI’s are OCD, you may never have a problem running 0w20. If you are going 7500 mile OCI, then I can see how 0w20 could be a problem in a DI engine with cylinder deactivation.

 

[swathdiver]

Does anybody actually know how long it takes for fuel dilution + contaminants to break down the oil to the point where it is no longer providing adequate protection?


We hear a lot about fuel dilution and wear breaking down the ow20 oil to basically nothing, but I never hear concrete numbers as to how long 0w20 would be considered good to use from the hardline 5w30 advocates. I mean surely it doesn’t break down within 3k miles?

Where I’m going with this is If OCI’s are OCD, you may never have a problem running 0w20. If you are going 7500 mile OCI, then I can see how 0w20 could be a problem in a DI engine with cylinder deactivation.

Depends on the engine, it depends on how hard the engine is used between oil changes. It depends on the fuel used, the cleanliness of the air going into the engine, etc.

The 5.3 does fine on 0W20 but the more powerful 6.2, especially when under high loads, experiences engine wear faster.

I'm sure companies like BlackStone Labs will have the data.

There's unconfirmed rumors that GM is already street testing deleted 6.2s and you can bet those engines are running thicker oil.

 

[vcode]

Does anybody actually know how long it takes for fuel dilution + contaminants to break down the oil to the point where it is no longer providing adequate protection?


We hear a lot about fuel dilution and wear breaking down the ow20 oil to basically nothing, but I never hear concrete numbers as to how long 0w20 would be considered good to use from the hardline 5w30 advocates. I mean surely it doesn’t break down within 3k miles?

Where I’m going with this is If OCI’s are OCD, you may never have a problem running 0w20. If you are going 7500 mile OCI, then I can see how 0w20 could be a problem in a DI engine with cylinder deactivation.

I recall seeing posts at 5K miles with less than 1% dilution. Funny, back in the 1960's the big 3 suggested 6K intervals for oil changes. Hard to believe that things have gotten much worse since then.

 

[vcode]

Depends on the engine, it depends on how hard the engine is used between oil changes. It depends on the fuel used, the cleanliness of the air going into the engine, etc.

The 5.3 does fine on 0W20 but the more powerful 6.2, especially when under high loads, experiences engine wear faster.

I'm sure companies like BlackStone Labs will have the data.

There's unconfirmed rumors that GM is already street testing deleted 6.2s and you can bet those engines are running thicker oil.

The 6.2l has been running 0W20 for over a decade now and up until the recall we weren't seeing any non-DFM oiling issues to speak of.