Another oil weight question

[Too_L8T]

We have a ‘25 burb premier with 5.3L - 18k miles. Should i use 5w-30? or the recommended 0-20. i just feel its too thin but i didnt engineer the motor

 

[OR VietVet]

Where do you live? Does the owner's manual give you options, depending on where you live? I have an 05 Tahoe 5.3 and have no idea what your owner's manual may say.

 

[blanchard7684]

We have a ‘25 burb premier with 5.3L - 18k miles. Should i use 5w-30? or the recommended 0-20. i just feel its too thin but i didnt engineer the motor

With the 5.3 0w-20 is “adequate”, 5w30 or 0w30 has a good margin of safety for things like high ambients , low rpm and high loads, and fuel dilution.

 

[Marky Dissod]

We have a ‘25 burb premier with 5.3L - 18k miles. Should i use 5w30?

Yes, nothing to do with feelings, everything to do with how motor oil works.
GM OE recommended motor oil for 6.6l L8T is Dexos 5w30. Outside of the continental US, GM OE recommended motor oil is usually 5w30.
So, yes, 5w30.

 

[B-train]

I agree, don't overthink it. Just use a good full synthetic 5w-30 and run it. I use it in all my vehicles, and even in all the ones with 0w-20 on the cap with almost 200k trouble free miles - in temps from -25F to 100F. Works fine.

Most GM commercial engines come with 5w-30......why? Because it works best, holds up to abuse better, and they aren't subject to CAFE gimmicks.

 

[Joseph Garcia]

Another vote for 5W-30 from me.

 

[ZKWBQD]

We have a ‘25 burb premier with 5.3L - 18k miles. Should i use 5w-30? or the recommended 0-20. i just feel its too thin but i didnt engineer the motor

I would only have the oil changed at a GM dealer. Should the engine fail, GM will aggressively try to deny your warranty claim. Initially, the dealer would ONLY use the sewing machine oil, (0W-20). However, starting in January of 2025, they will now use what I prefer, 5W-30. I asked them why they are now able to do this, they told me "there is a new sheriff in charge of the EPA".

 

[OR VietVet]

I would only have the oil changed at a GM dealer. Should the engine fail, GM will aggressively try to deny your warranty claim. Initially, the dealer would ONLY use the sewing machine oil, (0W-20). However, starting in January of 2025, they will now use what I prefer, 5W-30. I asked them why they are now able to do this, they told me "there is a new sheriff in charge of the EPA".

So, GM is saying they feel the 5w-30 is best for the engine and that the 0w-20 was only for MPG average and not because it protects the engine.

 

[Fless]

As I understand it, in 2025 the fines for non-compliance with existing CAFE (Corporate Average Fuel Economy) standards were reduced to $0.

There is currently an active proposal by the NHTSA to amend the CAFE standards, with Comments due yesterday:

Proposal info

Notice of Public Hearing here:

Public Hearing Notice

 

[Too_L8T]

I would only have the oil changed at a GM dealer. Should the engine fail, GM will aggressively try to deny your warranty claim. Initially, the dealer would ONLY use the sewing machine oil, (0W-20). However, starting in January of 2025, they will now use what I prefer, 5W-30. I asked them why they are now able to do this, they told me "there is a new sheriff in charge of the EPA".

is there any truth to this? documented? i never put any thought to that.

 

[West 1]

Everyone can believe what they want on the oil subject. The internal engine components are better protected by 5-30W than they are by 0-20W.
The vehicle may get 1/100 better MPG with 0-20W but that is the only advantage. Unless you live in extreme cold, like Alaska winters, you are better off with 5-30W.

Do you think GM builds a different engine to sell in Mexico or South America? GM does not recommend 0-20W outside the USA. Read between the lines. 5-30W is better.
If in a very hot climate, like Arizona or Las Vegas Where 100+ temperatures are common for long periods of the year 5-40W or even 10-40W would be even better.

 

[kurtibm]

"There is currently an active proposal by the NHTSA to amend the CAFE standards, with Comments due yesterday:"

A high percentage of the so-called "comments" were merely cut-and-pasted; presumably these folks were alerted by some media site to reply en-mass.

 

[Too_L8T]

Do you think GM builds a different engine to sell in Mexico or South America? GM does not recommend 0-20W outside the USA. Read between the lines. 5-30W is better.

I dont know, do they? Can you point me to where they don't recommend 0-20 outside the US? A shop manual or owners manual outside the US?

Not trying to be confrontational, it’s a genuine question.

 

[Fless]

"There is currently an active proposal by the NHTSA to amend the CAFE standards, with Comments due yesterday:"

A high percentage of the so-called "comments" were merely cut-and-pasted; presumably these folks were alerted by some media site to reply en-mass.

The comments are generally all that way -- many are boilerplate proposed and distributed by interested parties just to skew the regulators (who already know this and take it into consideration). My whole career was spent with communications companies (cable TV, mostly, and the Federal Communications Commission), and reviewing the public comments was part of the work.

Same with comments that are sent to State and Federal representatives.

 

[fondupot]

I personally will stick with my Amsoil 0W20 until our extended warranty is up. Won't go past 5,000 miles oil intervals or 6-8 months. I will consider switching to 5W30 once my extended warranty is up though.

 

[ZKWBQD]

So, GM is saying they feel the 5w-30 is best for the engine and that the 0w-20 was only for MPG average and not because it protects the engine.

The car companies were under intense pressure to maximize fuel economy. Therefore, reliability and engine life were sacrificed for a small increases in MPG. Thinning out the oil was one way to slightly increase MPG. As long as the engine could limp across the warranty period they were good. Standby generator manufacturers were ordered to reduce their exercise time from 12 minutes to 5 minutes. The problem is, that short exercise time was not enough to get the oil hot, and to drive out the water. This forced homeowners to manually exercise their generators to avoid moisture in the oil.

 

[2024 White Tahoe]

The car companies were under intense pressure to maximize fuel economy. Therefore, reliability and engine life were sacrificed for a small increases in MPG. Thinning out the oil was one way to slightly increase MPG. As long as the engine could limp across the warranty period they were good. Standby generator manufacturers were ordered to reduce their exercise time from 12 minutes to 5 minutes. The problem is, that short exercise time was not enough to get the oil hot, and to drive out the water. This forced homeowners to manually exercise their generators to avoid moisture in the oil.

In June 2024 I had a local authorized Generac dealer install a Generac 26kw natural gas standby generator at my home.

The dealer programmed it to exercise (run) for 15 minutes, every seven days. I have the option of changing it if I want.

Please provide proof of your post that stated, “Standby generator manufacturers were ordered to reduce their exercise time from 12 minutes to 5 minutes.”.

 

[BacDoc]

My 2024 Tahoe with 6.2l was inspected for the recall and passed so they put in 0-40W.
I put enough miles (about 3k) to do another 0-40W oil change.

I couldn’t tell any difference in driving, and absolutely no discernible decrease in fuel mileage per gallon according to the data on the DIC.
City driving and steady highway driving at 70-80mph show no difference in mpg.

Just have to add I did get the GM/Brembo performance brake kit installed on the front too and that worked out great for braking

 

[blanchard7684]

My 2024 Tahoe with 6.2l was inspected for the recall and passed so they put in 0-40W.
I put enough miles (about 3k) to do another 0-40W oil change.

I couldn’t tell any difference in driving, and absolutely no discernible decrease in fuel mileage per gallon according to the data on the DIC.

Thank you for reporting back on this. Add this to the thousands of similar cases where the 0w40 doesn't tank fuel mileage.

 

[jfoj]

I have not had 0W20 in my 2024 6.2l Yukon since 544 miles, have been running 0W40 Pennzoil Ultra Platinum with OCI at 50% on the indicator. Also installed a Range DFM and ASS bypass module at 274 miles. I have over 15k miles on the truck now and I think the lifetime average fuel economy is close to 18 MPG.

Between the 0W40 oil and the DFM/ASS being disabled I guess I should have seen my fuel economy tank??

I see no significant decrease in fuel economy and expect much greater overall reliability in the long run with the way I have my vehicle configured.