6.2L Engine... What gas are you using?

[Blackhawkscrna]

I’ve had a 6.2 in 3 Yukon Denali since 2007. Always used 93, 0 engine problems. That being said, I have a z71 with 5.3 on order , and one reason is I’m tired of spending the extra on premium.

 

[Monkey01]

Running 87 does damage to the engine over time with regards to the 6.2. We see lots of broken rings and pistons on these forums because of it after many years of abuse.

Thank you. Premium it is.

 

[Geotrash]

While the ECM is designed to protect the engine when run on low octane fuel, it's not a perfect system and there is only so much it can do. We now have 15 years of experience on here with people running the 6.2 and have hashed this out in the other gen. forums several times. Several people have run their engines instrumented to compare timing and pre-ignition events (which are mostly inaudible on these) and the data is compelling on 87 vs 93. That, taken with the evidence that piston failure due to damage commensurate with running them on 87 is a common failure point, and the evidence is clear: The 6.2 will have problems over time if they are run on 87. You'll get away with it for a while, but engine longevity will be affected - especially under high load situations.

Nice summary of a 6.2 failure here from a guy who tears down a lot of engines. Link goes to the correct starting point to save you time.

 

[Monkey01]

While the ECM is designed to protect the engine when run on low octane fuel, it's not a perfect system and there is only so much it can do. We now have 15 years of experience on here with people running the 6.2 and have hashed this out in the other gen. forums several times. Several people have run their engines instrumented to compare timing and pre-ignition events (which are mostly inaudible on these) and the data is compelling on 87 vs 93. That, taken with the evidence that piston failure due to damage commensurate with running them on 87 is a common failure point, and the evidence is clear: The 6.2 will have problems over time if they are run on 87. You'll get away with it for a while, but engine longevity will be affected - especially under high load situations.

Nice summary of a 6.2 failure here from a guy who tears down a lot of engines. Link goes to the correct starting point to save you time.

Thank you. Very informative.

 

[WalleyeMikeIII]

My 2022 Yukon Owners manual says 91 is the recommended. I looked at the 2021 manual online and compared. 2021 recommended 93 They did change it to 91 this year. Not sure if there was a change to the engine tune, or just “marketing.” I was pleased with this because finding 93 in MN is difficult. 91 is available as the “premium” everywhere in the state. Our Costco has 92…and it’s about $0.60 less than the 91 everywhere else…I’m only on my 2nd tank, but it’s been Costco for me.

 

[Fless]

While the ECM is designed to protect the engine when run on low octane fuel, it's not a perfect system and there is only so much it can do. We now have 15 years of experience on here with people running the 6.2 and have hashed this out in the other gen. forums several times. Several people have run their engines instrumented to compare timing and pre-ignition events (which are mostly inaudible on these) and the data is compelling on 87 vs 93. That, taken with the evidence that piston failure due to damage commensurate with running them on 87 is a common failure point, and the evidence is clear: The 6.2 will have problems over time if they are run on 87. You'll get away with it for a while, but engine longevity will be affected - especially under high load situations.

Nice summary of a 6.2 failure here from a guy who tears down a lot of engines. Link goes to the correct starting point to save you time.

He tears down a variety of engines, and I find his videos interesting and informative. Along with some subtle humor/sarcasm.

 

[Stbentoak]

My 2022 Yukon Owners manual says 91 is the recommended. I looked at the 2021 manual online and compared. 2021 recommended 93 They did change it to 91 this year. Not sure if there was a change to the engine tune, or just “marketing.” I was pleased with this because finding 93 in MN is difficult. 91 is available as the “premium” everywhere in the state. Our Costco has 92…and it’s about $0.60 less than the 91 everywhere else…I’m only on my 2nd tank, but it’s been Costco for me.

If you are lucky enough to have a Costco or Sam's club with fuel near you, this is a No Brainer really. Their Premium is equal or less price than RUL at normal stations around us. Ya, you may have to wait a little bit, but saving 8-10.00 a fill-up is well worth it. I wish they sold diesel....

 

[WalleyeMikeIII]

What's everyone's thoughts on the switch from 93 --> 91 in the owners manual...do you think they made any engine tune changes, or just did this for Marketing?

 

[Geotrash]

What's everyone's thoughts on the switch from 93 --> 91 in the owners manual...do you think they made any engine tune changes, or just did this for Marketing?

It's likely just a correction. The manual should have stated 91 from the beginning because as previously mentioned, 91 is the highest you can get in the mountain states. 93 isn't sold there because it isn't needed at higher elevation. Normally aspirated engines lose about 3% of their horsepower for every 1000' above sea level due to thinner air. Thinner air = less compression, less compression = less pre-ignition potential so 91 prevents it there as well as 93 does at lower elevation. I would still run only 93 at lower elevations.

 

[WalleyeMikeIII]

It's likely just a correction. The manual should have stated 91 from the beginning because as previously mentioned, 91 is the highest you can get in the mountain states. 93 isn't sold there because it isn't needed at higher elevation. Normally aspirated engines lose about 3% of their horsepower for every 1000' above sea level due to thinner air. Thinner air = less compression, less compression = less pre-ignition potential so 91 prevents it there as well as 93 does at lower elevation. I would still run only 93 at lower elevations.

Fair enough, Minnesota is only 800-1100' above sea level, but the state mandated "premium" is min 91, which is what is mostly available...there are a few 93's around...but not many. Costco is 92. Net, do I run 91, 92, or 93 (priority being engine longevity) or should I imagine that any of these is ok?