Are you still using premium gas?

zelmo · June 11, 2022

There have been threads on here before regarding the use of regular vs premium gas in the 6.2L. I used to always use premium in my 2020 Denali. Recently the spread between them has reached $0.80 in my area so it isn't just a couple dollars more on a fill up now.

I started using regular and really don't notice a big difference in performance. I haven't tried to figure out the difference in mileage yet. Has anyone done that?

reeseb · June 11, 2022

I have never put anything other than L87 in my tank and have never had any pinging. My mileage seems to be on par, too. I get about 19 on the freeway. Chevy recommends that I use premium, but I recommend that I don't.

Edited June 11, 2022 by reeseb

dkmoneypit · June 11, 2022

Did this a few years back during the winter. I noticed the mpg went down. If I remember correctly it was down about 1 to 1.5 mpg.

Wiggums · June 11, 2022

I use premium gas in mine since I leave it parked for weeks. I don't think I've filled up in three months.

Denali_1500 · June 11, 2022

I have never used anything but 87 octane in my 2020 High Country HD with the 6.6L and my new 2022 Denali with the 6.2L.Never had a single issue and I dont expect any.

The reason is performance. The PCM is programmed with Low octane tables and high octane tables both. It will move to the low octane tables based on the ping ( KR ). The Low Tables are designed for 87. Yes, you will have a slight performance lost, but unless you are heavy towing or drag racing it, then the Low Octane tables will handle your drive with no issues.

swathdiver · June 11, 2022

You knuckleheads running 87 in your 6.2s let us know when you sell your truck so we can avoid it. Broken rings and pistons are in the motor's future.

Y'all ought to get the motor you can afford. As for me and my house, we will always burn E85 or 93 in our FlexFuel vehicles regardless of price. God provides for our needs.

June 11, 2022

2 hours ago, swathdiver said:

You knuckleheads running 87 in your 6.2s let us know when you sell your truck so we can avoid it. Broken rings and pistons are in the motor's future.

Y'all ought to get the motor you can afford. As for me and my house, we will always burn E85 or 93 in our FlexFuel vehicles regardless of price. God provides for our needs.

They will not. Ever heard of knock sensor? Are you WOT at every chance? Towing? If not, then nothing will happen. Also, I assure I can afford 20 dollar a gallon gas if I wanted. That doesn't mean I will blatantly piss away 10 bucks a fill up if I'm not towing or drag racing my truck. But please, tell us all how you know more than everyone else.

Edited June 11, 2022 by 1454

June 11, 2022

8 hours ago, zelmo said:

There have been threads on here before regarding the use of regular vs premium gas in the 6.2L. I used to always use premium in my 2020 Denali. Recently the spread between them has reached $0.80 in my area so it isn't just a couple dollars more on a fill up now.

I started using regular and really don't notice a big difference in performance. I haven't tried to figure out the difference in mileage yet. Has anyone done that?

I put 20k on my truck driving back and forth to Jersey from NC last year and saw between 20.5 and 21.5 regardless of 87 or 93. The only thing that gave me actual more mileage was using non ethanol fuel. Which inherently makes sense because ethanol is less energy dense. 88 gave a solid 22 mpg every trip.

swathdiver · June 11, 2022

39 minutes ago, 1454 said:

They will not. Ever heard of knock sensor? Are you WOT at every chance? Towing? If not, then nothing will happen. Also, I assure I can afford 20 dollar a gallon gas if I wanted. That doesn't mean I will blatantly piss away 10 bucks a fill up if I'm not towing or drag racing my truck. But please, tell us all how you know more than everyone else.

They do, it is not speculation, those of us who pay attention have witnessed it.

Your high compression engines knock/ping while driving around town on that 87 swill. You cannot hear it. You take off from a light, the motor knocks and the computer pulls timing. You go to pass a guy, even without downshifting, the motor knocks and the computer pulls timing. 1000 more times on your trip to the mall and back. You don't think that will take toll day after day, month after month, year after year?

I don't know more than everyone else, I paid attention and learned it here. You can too if you do your research.

Last time at the drags I took a video from inside the cab, from the stands and took a Snapshot with my Tech-2 to show you guys that the motors do knock and you cannot always hear it. I am not tech savvy enough put three videos into one but someday my kids might slow down and help me post it for y'all.

Myself and others have posted videos from youtube of 6.2s that came apart because of prolonged use of low octane gasoline.

June 12, 2022

I went to tech school first for automotive technology, and then for a BSME. I didn't learn what I did from a message board. If you aren't under heavy load, cylinder pressures aren't enough to cause detonation. No manufacturer is going to sell a engine today that a slightly lower octane will cause them warranty work. But yes, you know more than everyone who has shown this isn't the case because someone posted a forum topic on "muh 87 causing detonation, omg."

Big_Kahuna · June 12, 2022

last year I rent a Cadillac Escalade with 6.2 to go on a long trip and yes if you use 87 in that ****** she will knock , I have heard it knocking , those 6.2 do not like 87, 89 was much better but she love 91 and above.

Chevyguy273 · June 12, 2022

Yes I am. I’ve always used 91.

Byrds8 · June 12, 2022

If it was going to damage the engine to use 87, then 91+ would be required vs recommended.

swathdiver · June 12, 2022

13 hours ago, 1454 said:

I went to tech school first for automotive technology, and then for a BSME. I didn't learn what I did from a message board. If you aren't under heavy load, cylinder pressures aren't enough to cause detonation. No manufacturer is going to sell a engine today that a slightly lower octane will cause them warranty work. But yes, you know more than everyone who has shown this isn't the case because someone posted a forum topic on "muh 87 causing detonation, omg."

Well, you know so much that isn't so.

Make sure you let us know when you sell your car so we can all avoid it.

Grumpy Bear · June 12, 2022

https://pickuptrucktalk.com/2020/10/misleading-these-trucks-recommend-or-require-premium-fuel/#:~:text=GM recommends using 93 octane,economy you must use 93.

Recommends and Requires do not have the same meaning.

Question! As GM's RECOMENDED 93 is not available everywhere in the USA does that mean those who live in areas without 93 can 't own a 6.2? :dunno:

Kiddo's my little much hatted by most 4.3 RECOMMENDS 87 octane and pulls up to 10 degrees KIR on every hill or major headwind. It's also a Flex Fuel vehicle and pulls zero KIR when using something over 40% ethanol and more interestingly does about 3% better that the carbon balance would indicate which speaks to GM's claims the RECOMMENDED USE of higher octane fuel will ENHANCE PERFORMANCE AND MILEAGE.

IF KIR knocked rings out of motors there would be heaps of dead 4.3's littering the highways.

Does that mean others observations of damage are in error? Absolutely not. Some knuckle heads think towing heavy on 87 is a good idea and they will suffer for that mistake. KIR will not pull an infinite amount of timing.