6.2 vs 5.3 and premium gas

[tomgilk]

I'm only here to chip in that Premium fuel at Costco is just a few cents more than regular everywhere else. I filled up with premium this morning for $3.19 a gallon and most other stations are close to $4.

 

[PatDTN]

I'm only here to chip in that Premium fuel at Costco is just a few cents more than regular everywhere else. I filled up with premium this morning for $3.19 a gallon and most other stations are close to $4.

Ditto Sam's Club near Knoxville. Actually beats Costco by a couple of cents. I do feel a tiny seat of the pants difference in favor of Costco.

 

[swathdiver]

Ditto Sam's Club near Knoxville. Actually beats Costco by a couple of cents. I do feel a tiny seat of the pants difference in favor of Costco.

Costco is Top Tier and Sam's doesn't advertise it as such but could be depending on who they buy from at the time. Actually tried to buy some today but the lines were longer than I had patience for!

 

[Stbentoak]

Costco is cheap but always 16 cars deep. Not worth the wait….

 

[SSGUNNER]

Costco is cheap but always 16 cars deep. Not worth the wait….

It is when you got that auto stop/start.

 

[Z15]

Premium is recommended and there is a label on the filler door saying so as well as in the owners manual. They shy away from saying required because the ecm (computer) will try to adjust for the lower octane fuel by detuning the engine. But keep in mind although it may say 87/89 on the pump it could be less with no-name brands.

I purchased my first 6.2L in 2012 (Sierra Denali) after having recurring problems with 2008 Sierra 5.3L. I have on occasion been forced to use 87 or 89 because that pump was out of service at the time (broke or no fuel). In those instances I could feel the difference in performance because leaving my house in one direction I have a 5 mile up-hill grade and I noticed the hesitation with 87. While you may not hear anything these engines are affected LSPI (low-speed pre-ignition). See pic below on the results of LSPI.

I have NEVER regretted getting the 6.2L, matter of fact I won't even consider buying anything else. I have had (all new) Sierra Denali's, 2012. 2015, 2017, 2021. All I keep for exactly 3 yrs and traded and traded when GM offered employee pricing for everyone or 0%.

 

[petethepug]

Forgive me, iphone in one hand, cuppa coffee in other hand and just noticed I was in the outskirts of the 2021 forums vs 07-14 land. ...

I recognize the difference in low and top grade fuel here in CA mostly by the lack of the motor refusing to kick down going up hills. We’re 87, 89 & 91 octane. The difference in the 93 octane available in TX was a blast. The truck had been gone through for a complete pre-delivery inspection and in top tune. Instant power delivery.

By the time it got back to Cali the honeymoon was over until … was discovered locally. I was happy with a 25¢ savings from Costco. With e85 the 6.2 is a very happy camper at the expense of MPG. I get 5-12 mpg on e85 depending on my idle vs. Highway driving.

I realize this is about choice A or B but leaving out plan C or e85 based on 100+ octane is missed. A $2 to $2.5 a gal savings is a $50+ savings ea fill up. The discernible difference is the frequency in fill ups or a change from about 250/280 to 190/210 miles per tank.

It’s obviously a logistical thing if you can get , and get it on the cheap. I just can’t believe, for the moment at least, we get the 6.2’s full 405 hp and save over $2h a month on fuel cost. The savings is paying for the needed rear main seal, oil pan gasket & trans service since the Esky just hit 150k mi.

 

[a4edwin]

It is when you got that auto stop/start.

It’ll be the same after you have to replace the starter. At least that’s how I feel about that.

 

[SSGUNNER]

It’ll be the same after you have to replace the starter. At least that’s how I feel about that.

I actually went today to fill up, 20 min wait. Could of been worse. Only options were 87 or 91 so went with 91 at 3.99 a gallon.

Honestly, I don't really miss the 6.2 or regret opting for the 5.3 and feel its sufficient. Wont be racing off the line at the light or for passing and believe me the passing capability on the 5.3 is pretty good and not lacking anything. If I felt I needed a need for speed I'd have opted for the 392 wrangler or Jeep SRT. Even considered the 392 charger but those are due for a refresh soon and was coming from a jeep already so...Tahoe it is

 

[DollyDenali]

My wife’s previous vehicle needed premium… put in 87 and it would throw a CEL. Switch back to premium CEL went out…all I need to know….

Same happen to my '07 Escalade. Girlfriend put in 87 the 2nd time and it ruined my O2's and cat's