What kinda fuel y'all run?

[sumo]

Top tier gasoline for me. Shell, Mobil. I have no choice anymore premium 93 all the time

 

[bigT63]

So... looks like all for gasoline and none for ethanol... I don't see a benefit with heavy ethanol blends.. I feel more cons than pros. Just asking every one on here since I'm not an expert on fuels. I've always been a diesel guy and never paid attention to the ethanol pump until today. I believe the 105 octane is to get the BTU #'s close to gasoline. Maybe gas stations get more RIN credits from the government when they sell more E fuels.

 

[sumo]

I bought 105 octane before. 10 bucks a gallon

 

[Dlayne]

IICR, vehicles with the LQ9 (Silverado SS, Escalade, etc.) were recommended to run 91 or higher, but not required. I don't recall the exact verbage, but the manual stated something to the effect of "reduced performance" if octane lower than 91 was used. GM's of that era were known to have conservative timing tables. So, you could run 87, but don't run it hard or you may get pinging and even further retarded timing.

Agreed. 87 might be fine when daily driving, but just add some weight on the hitch and climb a mountain or as you mentioned at WOT and my previous LQ9 would ping like crazy. Previous 6.2 ('07) was the same (even worse with the tune, but so much fun). So, nothing but 91+.

 

[BK76]

So... looks like all for gasoline and none for ethanol... I don't see a benefit with heavy ethanol blends.. I feel more cons than pros. Just asking every one on here since I'm not an expert on fuels. I've always been a diesel guy and never paid attention to the ethanol pump until today. I believe the 105 octane is to get the BTU #'s close to gasoline. Maybe gas stations get more RIN credits from the government when they sell more E fuels.

Same boat... been driving a Diesel for the past 4 years and now I am using the 17 Tahoe as the every day driver. Been putting 87 in the whole time, but hadn't thought about the higher gases. Saw online once that unless the car calls for it specifically, then don't pay the extra money cause it won't do anything for you.... but after reading all the comments above, i may jump up a notch and see how the lady performs. only at 3500 miles now

 

[Pops McGee]

only 93 in mine

 

[Smrtss1]

'12 Esky.........premium. Benefit of rewards points cards, knocks some of the cost off.

 

[AZCreeker]

We have a 15 suburban with the 5.3, and for about 3 months I noticed ping under load and lots of harshness when reving it to the higher RPM, after reading a bit here and there, I decided to try to run MID grade, which here in AZ is 89 from Shell
RIGHT AWAY: no more ping and smooth all the way to the top.
Needless to say I will keep putting at least 89 in.

 

[08HoeCD]

Just read that JennaBear recommends at least 89 octane for the 5.3 engine due to its compression ratio.

Will do.

 

[iamdub]

Higher octane fuel should not be confused with higher quality fuel. So many people put "premium" in their cars because it's labeled "premium" and it makes them feel all warm and fuzzy inside that they're putting "only the best" in their vehicle. It's not a cleaner or more refined fuel, it just has a higher level of octane. Some brands may put additional additives in their "premium" fuel, but that would be the only exception. The short of it is that octane makes the fuel less volatile/explosive. So, if you have an engine that doesn't need reduced volatility fuel, chances are that you could actually reduce that engine's efficiency (power) by using high-octane gasoline. Some engines have higher compression and/or more advanced timing, and running lower octane grades ("more explosive") gasoline can cause preignition (detonation/pinging/spark knocking).

As for the 5.3, it SHOULD require regular 87. I would hear some ticking that sounded like a slight and random exhaust leak when accelerating at full throttle and reaching the upper RPMs. Just for kicks, I tried 93 octane at this last fill-up and I'm pretty sure it didn't do it the short time I drove it. I only use Shell or Chevron and non-ethanol when/where available. I didn't get a chance to drive it much on that tank and my gf has filled it again, but with 87. I'll see if the ticking has returned and try mid-grade if it needs another fill-up.