Does a 2024 Z51 with 6.2 require premium fuel?

Damn...... I'm going to buy a commercial popcorn machine!

Ive got a buddy who sells automotive polishes that [can] have a number of "steps" required in the application of them. I remember asking him once if I really "needed" to use one of the steps in the process, and he said, "Do you have to? No. But then again you can use steel wool on your paint if you want to, too. But I wouldn't recommend it."

I initially put 87 in my Denali. It obviously ran without any real issues -- but I could hear it pinging when getting on the gas, heading up a hill, for instance. Since putting premium fuel in it, I haven't heard it ping under the same load. So, the higher octane is definitely providing a useful service.

I've also learned recently that my truck's VIN is on the potential-full-engine-replacement watchlist. If high octane does ANYTHING toward mitigating an engine failure, then it'll be worth the added fill-up costs.

KMeloney said:

I've also learned recently that my truck's VIN is on the potential-full-engine-replacement watchlist. If high octane does ANYTHING toward mitigating an engine failure, then it'll be worth the added fill-up costs.

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I believe that list is more than a "watch list," It is a 'Customer Satisfaction Program' for oversize lifter bores, and the only fix is a new engine. And GM is requiring dealers to replace these engines. The salient text in the bulletin is:

"In summary, whenever a vehicle subject to this program enters your vehicle inventory or is in your facility for service through May 31, 2026, you must take the steps necessary to be sure the program correction has been made before selling or releasing the vehicle."

Dodging this replacemet is kind of like the same logic as "should you use 91+ octane." Should you run w/ oversized lifter bores? You Can, but GM is not recommending it...

For many years cars have had Knock sensors, which prevent any issue using a lower octane gas where premium was recomended. I use Regular in my Lexus sedan and my V12 BMW with no issues that I'm aware of.

WalleyeMikeIII said:

I believe that list is more than a "watch list," It is a 'Customer Satisfaction Program' for oversize lifter bores, and the only fix is a new engine. And GM is requiring dealers to replace these engines.

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Right. I only meant that I am watching out for a catastrophic engine issue (maybe more than others whose trucks aren't on the list) while continuing to hope that the truck stays problem-free.

Otherwise, yeah, I have some peace of mind now knowing that if it does fail, GM will replace the whole engine.

stevedonato said:

For many years cars have had Knock sensors, which prevent any issue using a lower octane gas where premium was recomended. I use Regular in my Lexus sedan and my V12 BMW with no issues that I'm aware of.

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Have you blown up a modern BMW engine before? I have at VIR at a HPDE. It's expensive to the point where you might as well throw your car into a car shredder.

If you don't believe me, I can prove it to you with your car.

I guess I don't understand why anyone would WANT the computer to pull timing if it doesn't need to with higher octane.

KMeloney said:

Right. I only meant that I am watching out for a catastrophic engine issue (maybe more than others whose trucks aren't on the list) while continuing to hope that the truck stays problem-free.

Otherwise, yeah, I have some peace of mind now knowing that if it does fail, GM will replace the whole engine.

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The way I read this CS program bulletin, GM doesn’t want you waiting till it fails, they want to replace it ASAP.

WalleyeMikeIII said:

The way I read this CS program bulletin, GM doesn’t want you waiting till it fails, they want to replace it ASAP.

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Ok, I see where you're coming from. No, that's not my understanding at all after speaking with my dealer's service manager. I understand it that nothing is to be done prior to a failure -- but that upon a failure the engine is replaced with no questions asked.

KMeloney said:

Ok, I see where you're coming from. No, that's not my understanding at all after speaking with my dealer's service manager. I understand it that nothing is to be done prior to a failure -- but that upon a failure the engine is replaced with no questions asked.

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Might want to call GM...because the txt says: "In summary, whenever a vehicle subject to this program enters your vehicle inventory or is in your facility for service through May 31, 2026, you must take the steps necessary to be sure the program correction has been made before selling or releasing the vehicle."

Read the whole bulletin I linked above...why would they tell dealers to put a stop sell on any new vehicles in inventory...clearly they don't have blown engines...(we have this thread off topic, but if I were you and on the list...I'd be asking more questions), and why would they use words in the customer letter saying they want to prevent the situation from occurring...

Oversized lifter bores will ultimately blow your crank bearings, as loss of oil pressure will result. The only fix is a new engine, and GM agrees. Hence this program. You have a new engine coming if you are on the list.