Aren't SC's built for 91? How would that be different from mine built for 87 and running 89?

 

ss/sc's are meant for 91 or higher. but anything over 93 is too much for a stock ss/sc also.

 

I use 93 in my SS/NA. No problems for an entire year.

THe SS models are recommended to use 91 OR HIGHER octane. I wouldn't recommend using it in an LS/LT model (because they aren't tuned for it) but it's fine in the 2.4l and
2.0l engine.

And I would also recommend Top Tier gasoline if you plan on keeping your car past 100K miles. Updated detergents in the gas

 

yeah i just checked the manual and it said for the 2.4l ss/na engine AND ss/sc 2.0l engine to use 91 or higher...im not sure if bp offers 91.. i think they have 93...but it says or higher so shouldnt it be ok?

and i just never thought our cars needed higher than 87.. i guess i shoulda checked.. but ive put quite a few miles on it with the 87... and right now ive got nearly a full tank of it to burn off before i put 89 or 93 in(91 if bp has it)

my car has never had any problems thankfullly... but i have put thousands on it using 87... so hopefully my car will be ok

 

You will not gain any HP over stock for the 93 octane. Since that is what you are supposed to be using.

You may notice an increase of power from it, meerly because you may have been losing power all along from the 87 octane.

The 2.2L is the only ecotec that should be using 87.

 

If you use the cheap stuff what will happen is the cars ECU will pull timing to stop detonation which will reduce hp so if you run what your supposed to you may see a gain cause the car won't be in crap gas mode.

 

Jack, how about the other way around? Using 89 in a 2.2? Like I stated previously, I thought I saw a jump in mileage or could this just be a fluke? Any big downside to this?

 

it's a fluke. don't use 89. i promise it's not helping you any.

 

lol alright so maybe my car hasnt been harmed

 

SC's built for 91.......dem's jokes foo' !

Boy, when I see a stock knock free SC on 91, i'll let everyone know.

There is a only so much the car can compensate before damage is caused. In the SC 8* of KR for example.

 

lol i understand the later part but your first comment sounds like your drunk

 

This is a nice little chart for everyone here:


Cobalt SS/SC (2.0L) = 91
Cobalt SS/NA (2.4L) = 89
Cobalt LT etc. (2.2L) = 87

So please do not fill up with more octane than you need. With gas prices this high, your just throwing money away with nothing to show for it.

 

But make sure your using top tier fuel.

 

actually in my manual it says to use 91 or higher.

it says for both the 2.4l and 2.0l engines to use 91 or higher.. it doesnt say anything about 89.


and btw i picked up some octane boost the other night to get my car up to 91 where its supposed to be.

 

91 octane, while recommended...is not high enough IMO for the ss/sc
but unfortunately thats the best some people can find.

my ss/sc, along with many others im sure, gets knock with 91 octane.
91 octane + good octane boost almost completley gets rid of it
94 octane completely gets rid of it.

 

octane boost is worthless, save your money. it doesn't raise it anywhere near what people think it does.

 

I completely disagree.

Ive seen first hand what an octane boost is capable of.
and if you spend money on a GOOD one, you can get a goot 2-3 points of octane out of them easily.

 

one "point" is one tenth of an octane. so, 2-3 points of extra octane will bring you from 89 to 89.3 octane.

one "point" is not what it seems like.

even the best octane boosters will raise about 10-15 points, and what good is that for? 1 "real" octane. you're better off just getting better gas. but i stick to it, octane boost is a waste of money.

 

for 2.4s is 93 i think and up.

ryan.

 

i've used octane boost in cars where i think i got a bad tank of fuel, helped a little.

i use 93 all the time in my 2.4, 89 isn't for newer cars, it goes back to the 80s when 91-93 wasn't common.

for example, my 81 BMW requires 87, which, at the time, WAS the high test. then 89, then 91, now 93.

however, on an older car with a lot of miles, sometimes stepping "up" a grade will reduce some ping. like going from 87-89 on some beat ass old pick up.

 

no stock cobalt is 93 and up.

 

that is an old argument that isnt true these days.
they used to use that system to fool people into it...but the octane points they refer to on good quality boosters these days is ACTUAL octane points.

do a little reading about them
that 1/10th point argument has been around a long time. and if you buy a quality product like Lucas, or NOS racing formula....youll see that they even disclaim that right on the packaging



the results dont lie.

91 octane 4* of knock.
93 octane 1* of knock
94 octane 0* of knock

91 octane with NOS racing formula? 0* of knock.

 

no, acutally i bought some NOS Octane Boost, ran me about 11$

it says on the bottle "Increases Octane Effect Up to 6 Full Octane Numbers (60 points)

Treats up to 16 gallons of gasoline"

so i should be running 91 octane right now, next time i will just fill up with premium at the station which is either 91 or 93

 

Other than being completely wrong I like your chart
The manual book says to use a minimum 91 octane for the 2.4l engine, using less will cause a decrease in performance and mileage.

I can't imagine that the SS/SC could get away with less than 91.

And seriously, if you can't afford the extra two bucks per fill up, you shouldn't have bought a new car.

Nope. Recommended at least 91 Octane

 

there's a few out that are actually good. but 90% of the octane boosters out there are crap. nos is one of the good ones. and the other big thing i meant when i said it's not worth it, is like you said, it was 11 dollars vs. 2 at the pump.

if you have 93, and want to run 97, that's different. but that's not something you would wanna do just because.