What grade Octane should we use

[King Asoka]

I saw Duesergirl's post about what grade gasoline she should use in her 2.4. I thought it might be a good idea to discuss what everyone uses in there tank and why. Give your view of the pros and cons.

Im burning 92 octane in my 3.4L. (In Canada Chevron sells gas with 87,89,92,94 octane levels) I find i get better mileage at the higher octane level. I havent tried the highest octane gas yet, and i dont think i will bother unless i get some serious engine mods done. I also think it burns a little cleaner the higher you go, but that, im sure is debatable. I also find i get less engine knock. Im definatly no expert when it comes to this stuff. So I cant wait to hear what you guys have to say.

I use regular gasoline.. can't recall what octane level it is. I don't think I'll be upgrading anytime soon either, since gas prices here are topping 2$/gal for regular. >:\

To keep this conversation in one place I'm moving their post over here.
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duesergirl:
Ok, before anyone asks, I did a search and it didn't come up with anything very helpful. Nick touched on this in that silly thread about the kid with the stock 2.2 running 14 secs, but that was about it and didn't really answer my question.

So, my question is, what difference does it make what octane you put in the car? The reason I ask: I've been hearing lately that you should put in whatever it says in the manual, and not anything higher. Jimmy has always heard that it's good for the car to put in the higher stuff once in awhile, that it sort of cleans the engine out or something. He also says you're supposed to put in one of those bottles of cleaner in once in awhile too, and I said that's not necessary because most gas has engine cleaners in it now, but that's a different story. If it's bad for the car, though, I'd like to know for sure because I want to give him a definate answer before he kills our only means of personal transportation!

Oh, I put this here because that's what type of engine I have, and it is sort of an engine question, I guess. But if this is the wrong place, moderators, please feel free to move this thread wherever it should go!
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wy3134:
You are absolutely correct there in the sense that the manual is correct about the gas...unleaded will be perfect for the 2.2 and its perfectly fine to run premium maybe once a month during the winter and maybe a couple times during the summer, I buy the fuel cleaners at Autozone that match the mileage on my car, usually spending the $8 for the bottle that cleans most of the fuel system, rather than 3 diff. bottles that clean only specific parts of the fuel system. Hope this helps.....

It doesn't matter if you go higher than the recommendation in the owners manual, you just aren't supposed to go lower. The higher the octane rating, the longer and cleaner the burn of the fuel.

Case in point, in my Bronco I if I burn 87 I get around 13 mpg on the highway, with 93 I get almost 16 mpg highway. I don't quite understand it. The manual for that say use 87, but with a gain of 3 mpg it's worth running the higher stuff. Also I have been doing this going on 4 years now, with no adverse effects whatso ever. I was even able to advance the ignition timing without having spark knock, and felt a difference in power.

[Redog]

It depends on what mods you have done to your car. I find that if your running an intake (CAI or WAI) you might want to go to 89 (mid grade) but you can stay at 87 (reg) if you want. If you have a S/C or a turbo, you should run at least 91.

After I had my manifold done, on 87 I was getting 6 miles a gallon. I usually put 89 in all my cars but since the price of gas was going up, even last summer, I started to go with 87. With my WAI I was getting a little less MPG, like 23 city instead of 25, but after the mainfold was done, it went to 6 MPG city. Plus it take the PCM about 50 to 100 miles to adjust to any mod, but the lower octanes were just burning up too fast with the mainfold done. I can get about 32 to 35 MPG highway now but I did get 37 almost 38 once.

If you car isn't set up to burn more gas, then reg is fine. The higher octanes will leave too much carbon inside your engine, if used all the time

[johny_boy32]

i use 92 octane in mine and my mpg is really good.....I get somewhere between 24-26 in the city and about 33 on the interstate.

use what is recommenced. 87. I believe car and driver had and artical on this a while back. unless you have mods that require it your just throwing money out the window. and stay away from that blend made from corn. i heard horror stories about it eating gaskets and what not.

[ptrudel]

i just run regular...it's cheaper and no difference in performance(without mods)...i'll run super about once a month just for a little cleaning...and as for corn blended fuel, 99alero, ur absolutely right, stay away from that...many many horror stories around here about it...

[jamcllw]

I use the cheap stuff and I get on average about 34 mpg on interstate driving and about 25mpg in the city.

[johny_boy32]

like my auto teacher once said...its the same poop, just a different dog.

Good luck finding gas without ethanol for much longer. I try to stay away from it, knowing I don't have the harder seals, but it's hard to. It becomes more of a problem the longer it sits in your tank, so I don't worry too much, since I have to fill up at least once a week. Most newer cars have the harder seals, etc, that can handle ethanol no problem.

As for octane, I run 87 almost exclusively. I'll put in 89 or 91 when I'm towing, depending on how much 87 is in the tank when I start. I do get better mileage on higher, but I can't make myself pay the extra $0.10-$0.20/gal more.

[Oldsman]

Well here in Chicago area, due to emissions, all we have is ethonal gas.

I notice with that gas running 87 octane i get 24 in town and 31 on highway. with non ethonal 87 i have gotten 26 in town and 33 on highway. I use to normally run 87, sometimes 93. But since i got my MSD on, i am running 89-93. But with gas prices for 93 being $2.15-$2.25 a gal i think i am going to see how 87 does. 87 is just under $2.00/gal.

[ptrudel]

damn i feel dumb askin this, but how much does $2/gal come to in litres?

here gas is .839/litre...

like my auto teacher once said...its the same poop, just a different dog
^^^^ he`s right
i personally use 93 once a month, the only diff i see is my gas guage goin donw faster and milage is crap
all said is true 93 octane wil not hurt your car at all , i have seen some guys use 114 octane or a racing fuel, and completely burn the cat burn out the upper manifold
89 octane is good for our and most cars out there

[Redog]

Originally posted by 2000_olds_alero@Apr 28 2004, 11:00 AM
damn i feel dumb askin this, but how much does $2/gal come to in litres?

here gas is .839/litre...

There are 3.78 Liters in a gallon

[ptrudel]

:o holly poop...so in other words, ur payin approx $0.529/litre(.74/litre cnd)...i wish gas went down that low here...last time it went down that much was like 3 years ago <_<

I always use 87. It's runnin at $1.759 per gallon in Western PA.

87 for me too, gas in the Carolinas is running $1.60 for 87.

[BLK03GXS]

Last i bought gas i paid 88.9 cents a L.... b4 it was 77.9 issed: lol

But it has been said b4, even with "mods" exhaust and intake etc.. or even msn ignition... our engines are made to run regular gas, the only reason that premium gas exisits is for things like High compression engines, forced induction, and things like BMW's and Ferriaris... (the eco gets close to that at 10:1 compresion but still runs fine on reg BECAUSE THATS WHAT ITS DESIGNED TO RUN ON)
lol
As for runin the intermedate grades... they are all just designed to Suck the consumer in... i doubt you will find a car that calls for medium octane gas... either it runs on reg or premium... thats how it is
So unless you have serious mods, raised compression shaved head or forced induction.. its really a waste of time IMO..... but then we're payin a lot more for gas here... reg was 88.9 a L premium was 99.9 :rolleyes:

up here in green bay wisconsin its $1.86 for 87. But your state tax on gas is i believe almost $0.30/gallon!!!!