i use 87 fine, but try to use 93 when i can. the only reason i dont use just 91 is cuz like its only 1 cent cheaper usually so i figure why not.

but now gas is 4.09$ for premium..50$ to fill up my cobalt. ...i remember the good old days of 2006 when i got her and filled up for 35$

but yea you def notice a difference in power between the 2. i get better mpg using 87, but prob cuz i dont push it as hard cuz its not as fun

 

The car is tuned for 91 unless you have a custom tune. Stage 2 is 93 I believe. I know the manual for a stock SS S/C says 91 or higher is recommended but not required, but the computer will pull timing to compensate.

 

its like an extra 2.20 cents to fill up with premium with a 12 gallon tank. i think its worth it.

 

Looks like i'll be running 91 from now on.

For the $5 extra per full tank (yeah, thats what it is around here), I think it's worth it

BTW, it'll cost me about $62 (45L at 1.37/L for 91 here) with todays prices per fillup. (Thats $5.20 per gallon )

 

You must live in lower mainland, BC........'cause that's pretty much the exact price I pay. I gas up at Chevron though, so it's 92 octane.

 

Nah, Southern Ontario.

91 Octane Shell. (Say what you want but I can feel the difference with regular 87 vs shell 87 in some vehicles) (It's the only 'Top Tier' gas company in my neck of the woods too)

Well, actually we have Sunoco here, but i've never really trusted Sunoco gas, and i'm not totally sure why? Maybe it was something I heard about it?

 

Top Tier ftw... GM recommends running top tier in our cars. If you search around there's a sticky on it, I think in the Lounge. Where I am there isn't any top tier stations within 50 miles, so I just go to HESS and fill with 93 since they only have 87,89, and 93 and are generally the cheapest in town.

 

Be carefull where you gas up at.

Theres been plenty of reports recomending certain gas stations and stay away from the rest. Don't ever gas up at grocery store gas stations, Fas Gas and crap like that, even shell. Shell may be a bigger company, but their gas quality isn't much better than the grocery stores stuff. The reason behind it is because they use a lower quality of gas (much less effort put into refining) and theres a hell of a lot more debre in it (clogs your lines faster).

Chevron and Petro come out as high scorers though, and theres always one of those around on a long road trip.

 

Really eh? Just how did they earn top tier status then? Maybe some of the older shell stations have bad tanks, but I bet their tanks are tested every so often.

Also why can I FEEL the difference in our V8 Trailblazer (5.3L, with minor mods) between regular 87 vs shell 87?

Right now I drive across town whenever I fuel up, just to use the ONE shell station around here. People think i'm crazy, but it's only top tier for me!

 

Shell is rated the best gas out there...and shell makes me car run so much better...V POWER!!!haha 93octane FTW

 

Stage 2 might require 93 at sea level, but up here in the parts of the country where they don't sell 93, 91 works just fine thanks to the wonderful lack of air that also saps our power.

 

Isn't the Stage 2 cars tuned for 93? I know when I was Stage 2 I would get tons of timing pulled by running the 91 Octane.

 

How close to sea level are you? I'm a mile up and get zero KR on 91. They don't even sell 93 up here.

 

Our 2.4 will run fine with 89 octane. There will be no performance difference vs premium. I have tested this many times with my dashhawk and I have had no difference with my 0-60 or quarter mile times. I have also monitored my knock sensors and have had no problems with 89. Octane also doesn't affect mileage at all. 10% ethanol will hurt mileage a little but since it's cheaper I don't worry about it.

I am not saying theres anything wrong with running 91,92, or 93 octane but it is a waste of money if you think it helps your performance. I have never run 87 though and I imagine it is low enough that it would hurt your power.

 

have you dynod at all? i may try the 89 instead of premium

 

the 2.4 and 2.0 both reccomend using 91 octane, but will accept as low as 87 octane (the 2.0 doesnt reccomend it if going WOT though), however, the stgII 2.0 REQUIRES 91 octane. None of the engines are tuned for more than 91 octane, as that is the highest octane thats readily available in many states (such as here in CA)

go read your manuals....

btw, unless your getting knock with a lower octane, increasing your octane will NOT increase your HP unless you tune for it. so a stock 2.0l running 93 will actually see a slight decrease in HP over a stock 2.0l using 91 (since the ECM is tuned for 91 and not 93, the 93 will just burn slower without advancing the ignition timing, effectively reducing ignition advance)

 

I am pretty confident that when i use higher octane gas I have better throttle response and its peppier than when i use 87 octane. It may not be increasing horsepower but its doing something and runs noticibly better. I am no expert on the subject but when the manual says that the use of 87 octane may result in reduced performance i would say that there is definitely reason to believe that using the recommended gas could be making it run better. I think its tuned for the 91 octane in the same way some of the aftermarket tunes are tuned for 93 octane.

 

when you gentlemen say "it will take 87" do you actually understand what your saying?
or what happens when you do? or are you just hoping?

its amazing that after people explain it for so long, people STILL try to convice themselves of this stuff just to save a buck at the pump.

in the rare case that you completely and utterly granny drive your car, you could use 87 without knocking, but i highly doubt anyone on this board can claim to drive like that.
the other case, is if you specifically detune for 87, it can be done. i do it myself in the winter.

other than that, If you spent literally thousands more for a 2.4 or 2.0 model, then I see no point in putting your "performance engine" through a constant ritual of knocking to save yourself $2 a week on fuel.


your computers dont just magically know, oh look, he put 87 in, send a message up to PCM to remap the spark tables geeves, were getting ready for some **** fuel.

Oh no, your computer keeps trying to run the tune for the 91 octane (93 for S2) and every time it does, it will knock, and yank timing, then it will try and add that timing back, and knock again....
over and over and over.


Put 91 in your stock 2.4 and 2.0s
put 93 in tuned and modded 2.4s and 2.0s

doing anything less makes you look cheap and stupid.

 

!?

Go up to Cupertino/San Francisco, You'll find 93 there.

The reason they don't sell 93 in some places is due to the altitude. You don't need 93 when you're a mile up in the air. Down at sea level 93 is necessary. I would find it wierd if you can't find 93 in LA. Do the stations around you not sell 93?

 

So will an SS/SC


It called Knock Retard.

Look in a LE5 owner's manual.

It suggest the same thing for the SS/SC as the SS/NA.

 

Stage 2 is mapped for 93, not 91.

Oh, and go actually learn what octane is. It has *NOTHING* to do with how fast the fuel burns. Octane is a fuels resistance to self immolation due to compression. Higher octane is harder to ignite due to compression, which prevents pre-ignition of the fuel air mix and thus knock.

 

who told you that?
cuz its a load of bs.

 

There is some thruth in his statement.

You go waaaaay up into the moutains you will see 85/87/89


Which means those areas will be Steddy-free because they are too far for my POS Passport, and the Balt and Gix only sip on 93

 

I AM way up in the mountains. I regularly race at over 3000ft DA
there are over 10 stations in my city carrying 94, and are currently bringing in 96 to all those stations....

what truth is there in the statement?

 

I have seen it up in the towns by ski resorts.

I dunno.

Differenet areas are different.

94...I am jealous...we used to carry it around here