dbss88

around here i think its like 87...89...93

i usually just put 87 in my 2.4... but if i get alot more power i might just go the extra 20c a gallon for the highest octane

D4u2s0t

octane has nothing to do with power. use what the car is designed for, nothing more. you should not be using 87 in your 2.4 though, i would use 89 or 91

an0malous

you dont get more power from higher octane.
unless your tuned for it.

but since you obviously didnt read your manual....and your engine is knocking pinging, and crying from putting that 87 **** in it....
youll probably notice a nice boost in power if you give it the fuel your SUPPOSED to be giving it.

alleycat58

Exactly - simplest answer - you're not gaining anything if the car isn't tuned for it and could lose fuel. Although in a 2.4 I believe they recommend a minimum of 89. I know SS/SC it's 91 and up.

dbss88

knocking pinging?

and is it hard to get it tuned for the better octane?

D4u2s0t

yea i'm pretty sure for the 2.4 either 89 or 91 is ok.

an0malous

your car is designed to use premium fuel.
right now i garuntee you its knocking with 87 octane in it.

D4u2s0t

especially if he drives it hard. if he drives like an old man it's not that bad, but give it some gas and it's a

it's not something that you would want to look into right now.

OrngBalt

I just made the switch from 87 to 89 in an LT and I don't see a power gain, but I am noticing a gain in MPG. that's enough for me to splurge on 10 cents more per gallon at each fill up

dbss88

why isnt it?

well looks like ill have to take it easy on the car till my tank is up and get 89 or better

D4u2s0t

you're wasting your money. there's no benefit. stick to the 87. if you're seeing an increase in mileage it's because you're not burning your fuel properly.

there's lots of myths about octane and what it is, so for the record:

1) you do not get more power simply from using higher octane
2) you do not get better mileage from using higher octane
3) using improper octane, whether to high or too low, will HURT the performance of your car more than help.

dbss88

alright well thanks for the help, my last question, why isnt it something i should look into?(tuning for octane)

D4u2s0t

your car is pretty much stock right now. save your money and get some basic mods, learn about your engine, learn about tuning, timing, and what octane is. wikipedia has a great article that will help you understand octane and how it affects your car, take a look.

i would just recommend learning more about your car before you get into anything somewhat serious (like tuning your car) if you make mistakes with that stuff you'll blow yourself up, or ruin your engine.

i'm not knocking you at all by this, and i hope you don't take it that way, but from the questions your asking i'm guessing you're not super familiar with cars or engines in general. take the time to learn as much as possible, then you will figure out where to go from there.

dbss88

alright thanks man

D4u2s0t

you're welcome. and I added more to the above post in case you didn't notice.

FryLoch

iTrader: (5)

Your a little harsh...
Give the guy a little slack...

D4u2s0t

for those that don't understand octane, let me break it down very simply. octane is ONLY a gases resistance to detonation. nothing more. how does this affect your car?

to keep it simple, in our example let's say a car is supposed to run on 89 octane. that engine is set up to burn that gas to the fullest amount possible. the optimal point of detonation is called top dead center. or, TDC for short.

when you're using 89, which the engine is designed for, the gas is exploded at just the right time so that it forces your piston down, creating power.

now, if you use octane that's LOWER than you're supposed to, your engine is igniting it too quickly, before TDC. this means that your gas is exploding while your piston is still moving up. when the gas ignites, it bounces off the upward moving piston that wasn't ready to be moved back down, and creates "knock". not good for your engine.

it's the same but the opposite (doesn't make sense, right?) for octane that's too high. it burns slightly after tdc, which again is not ideal for power.

i hope this helps a little, i tried to keep it simple.

OrngBalt

Way to be Dust.... learn something new everyday

D4u2s0t

thanks... it's a very easy mistake, i used to think the same thing... if you don't know what octane really is, it makes sense, high powered cars use high octane, so it must mean more power.

OrngBalt

Do you use 87 or 89 in your 2.2? Did you notice any difference between the two?

D4u2s0t

i use 87.

Jimmys2007CobaltSS/C

iTrader: (1)

i usually use 91 ..but 2day i put in 93...and it felt kinda weird at first when i was accelerating the rpms go up and drop down fast when i led off..is that a problem...or is it normal..thats the first time i used octane 93...

D4u2s0t

don't use 93. it's too high

Jimmys2007CobaltSS/C

iTrader: (1)

damn....i did..woould dat kill my car now

D4u2s0t

no, just don't use it anymore and you'll be ok.