Regular or Premium Fuel?

[ryan's camaro]

I have a 2012 Camaro 2LT/RS with the LFX engine.
I know these V6 engines run on regular unleaded, but if I am willing to spend a bit more and give my car 91 octane premium fuel, would that make the car a bit more powerful? Could the LFX engine handle higher octane fuel?

[devildoc]

There are several threads that address this with the LLT.....I'm not sure how it would pertain to the LFX but I see no reason why you couldn't. I always put 93 oct when possible and the camaro seemed to run smoother and I would get better mpg. Of course in Cali you are stuck with 91 so I would just use that. Maybe try several full tanks of 91 and then compare your mpg with both?

[AUS10BMX]

The higher the better

I've now tried both, and the higher is very noticeable!

[KMPrenger]

Well, we really don't know as much about the Delphi ECM in the LFX versus the Bosch in the LLT, but if it works the same (advancing timing until spark is detected) then I would think running premium fuel would have a similar affect.

Some guys say they notice a small increase in performance, some just say the car seems to run smoother, and some say they can't tell any difference whatsoever.

One thing we do know, is that with the LLT running premium fuel will keep the computer from pulling as much timing as it does on regular.

[Fuel74]

I just picked up my 2012 2LT on Monday - had a full tank with Regular from the dealership. It sounded a little knocky - if you read the manual it says you may get spark knock if the octane is too low. I filled it up with 93 at about 180 miles. I'm up to 300 miles now and the engine definately sounds and feels smoother. Some of that may just be engine break in, but I'm sold on 93.

Feels a little more responsive as well, especially at lower RPM - pulled a u-turn today (legal in NC) punched it a little and it broke sideways real easy. Lots of fun!!

Can't wait to gets some mods on it. Vararam says they are working on an intake for LFX.

[BiG_TiMe]

i've always used regular but now after reading some threads, im gonna bump it up to either 89 or 91

[Final187]

before i went e85, I ran 93 all the time. You get noticeable performance over reg and I got better mpg with 93 so price just about equaled out!

[bmorecam]

If your delphi's kr thresh hold is programmed anything like our LLT then I would use the highest octane I can find at all times. I can't stand the way my LLT always show knock. That will be the first thing I will take care of once I get a chance to get my hands on HP tuners if it happens like it suppose to.

[booth8233]

When i ran 87 my tips were clean, when i ran 89 they got blacker but didnt really see no difference.. im gonig to try 91, but idk i heard its just a waste.? i guess different opinions lol

[bmorecam]

Originally Posted by booth8233

When i ran 87 my tips were clean, when i ran 89 they got blacker but didnt really see no difference.. im gonig to try 91, but idk i heard its just a waste.? i guess different opinions lol

Not a waste at all. Its a fact. Our ecm will pull timing like crazy with 87 but will do so less with higher the octane giving you a better optimal consistent timing

[booth8233]

well guess its just he said she said.. i actually did worse mpg with 89 then 87.. ill give 91 a try and see how that works out. thanks for the input bmorecam

[TJ91]

I dont think i can justify the 15c premium per litre here.
$95 to fill up with premium here, HELL NO

[scrming]

Originally Posted by booth8233

When i ran 87 my tips were clean, when i ran 89 they got blacker but didnt really see no difference.. im gonig to try 91, but idk i heard its just a waste.? i guess different opinions lol

The "its just a waste" is the OLD way of thinking... many newer cars will basically automatically tune themselves for the higher octane fuel....

[rock1962]

I noticed the difference with premium. I use shell (91 octane no ethanol) I could also get petro canada ultra 94 (94 octane has 10% ethanol). My question, stay with the 91 or go with the 94?