GenVibe - Community for Pontiac Vibe Enthusiasts

Being new, I don't know when the last time this was posted, but I am curious... Feel free to add your own answer!

91 - Since I drive a GT.

87- Since I DON'T drive a GT!!!

i use 89 in my base.i got my vibe march 05 and used 87 octane and around november 05 my cat converter died, during its death my milage decreased and upon its replacement (under a TSB) my milage never went back up so i started using 89 and that improved my milage a bit and is what i continue to use.on the turnpike between home and college using 87 i would average 26-29mpg and on 89 i average 30-40.i only hit 40mpg like 3 times, during those drives i was able to set the cruse to 70 and didnt need to pass people much.i've figured that the extra 10 cents per gallon of 89 is made up in the increase in gas milage.

And the experts tell us that higher octane is for lowering detonation. What do they know.

my friend's dad worked for petro-canada...he mentioned once that if i wanted 87 octane, i should go for 89 octane to account for any 'blips' in production...it insured that i would get at least 87 with statistically mostly closer to 89.if i went with 87..then statistically there would be some slightly lower.not sure how much i believe this but i wouldn't put it past any process to not behave properly!

"...but i wouldn't put it past any process to not behave properly!"Precisely why I go with mid-grade now. I only had 87 octane in it twice, back-to-back. I can't imagine the dealership went the extra mile with mid-grade, BUT you never know on that as well!

best we can get here is 90.i use 90 + Torco mixture = ~93-94 octane in LGTMav's been using 90 since he now has the unichip. he says it seems to drive a little better, but not too much of a difference he can tell.

93 here in pa i have gt , if you read the owner manual gt need the octane to run right

I have used both 89 & 87 and have noticed 2-3mpg better with 89 on my base with s/r and aftermarket muffler. It starts easier with 89 too, not that it won't start on 87, but with the 89 it fires right away. My '95 3.4l v6 camaro will not run on 89 or up. My '99 3.4l v6 Grand Am really did good on 89. What's up with that?

91 because of the Unichip.

mathteacher, i'm surprised to hear that your camaro wouldnt run on 89. my friend has a camaro i'll have to ask him what yr his is and stuffanother reason i use 89, in addition to the reasons others have posted, is because i notice some places are starting to add 10-15% ethanol. that ethanol will decrease your milage a lil.i've noticed the addition at sunoco stations here in PA

93 octane where i live (Spring Hill, FL). we get 87, 88, 89, 91 and 93.

87, I'm cheep

V, your actually spending more.i hope this isnt too confusingif you get 10 gallons of 87 for $x, if 89 is 10 cents more per gallon (over 10 gallons thats an extra $1) but using the 89 gives you 3mpg more that gives you an extra 30miles on those 10 gallons of 89, so in order to get the same # of miles on that fill using 87 you would have had to buy 1 extra gallon of 87 @ $2.60, you spent an extra $1.60 by choosing the 87 instead of the 89.

Quote, originally posted by coldmm803 »V, your actually spending more.SON OF A $%&^**$#$&%*&$!!!!!!!!!Thanks for the info

I'm using 87 because that is what the manual suggests. But, I have heard people say a higher octane can result in better MPG. But, I've also heard it isn't necessary for the engine to run properly.Manual says not to use methanol enhanced fuel, or a "reformulated" containing MMT. Both could cause damage.I'm new here. Has there been a thread that shares hints for improving MPG? It would be nice to have a list of things to try. For instance the octane, or some say synthetic oil, etc. What do you think?

I've read a dozen or more articles today regarding 87 octane gas vs higher octane gas and they all say higher octane will NOT increase mileage on a modern engine designed to run on 87, like the Vibe. Does anyone have info to the contrary? http://www.wistv.com/Global/story.asp?S ... od...s.htm

I plan on checking that after I get my scan gauge set up

Quote, originally posted by VforVIBE »SON OF A $%&^**$#$&%*&$!!!!!!!!!Thanks for the infoTo-may-to, to-mah-to. You call it "info", I call it "math"... We use 87 in the Vibe, and 91-93 in the Maxima (depends what the station carries for "premium").

Quote, originally posted by djb383 »I've read a dozen or more articles today regarding 87 octane gas vs higher octane gas and they all say higher octane will NOT increase mileage on a modern engine designed to run on 87, like the Vibe. Does anyone have info to the contrary? I'd like to see that too. If true, my mixed driving would net me about 35-36mpg.

It's true. The octane itself doesn't give you a thing except resistance to knock(explode) so low octane has just as much power. You can however get better mileage if your a lead foot or carry loads where the engine may knock under higher load situations. That will cause the timing to retard and cost you mileage but even then, you shouldn't see much improvement from higher octane unless 87 wasn't correct to begin with and the motors retarded a great deal of the time.

Quote, originally posted by scott_h »To-may-to, to-mah-to. You call it "info", I call it "math"... I hate math

87/89 - whatever they sell as regular - for the G6.

i wear a wizzard hat while i pump my gas and have noticed a 3-5 MPG increase

i use 87 octane mainly. But if filling while in Iowa 89 is usually cheaper and i'll go with that.

"in Iowa 89 is usually cheaper and i'll go with that."I believe it's cheaper there because it's partly ethanol. Since ethanol has somewhat less energy content than gasoline I'd expect the mpg to go down slightly unless the engine was running poorly on 87. So going with the 89 blend may not save you any money despite the lower price/gallon - support for Iowa's corn/ethanol economy is another matter.

Do I look on eBay for one of those?

93 for the GT. We don't have much 91 around here, usually just 87, 89 or 93 at the pump.

have been using 87 in the awd but today i am trying out 89

I have had several high performance engines and only one pinged on regular. That was my 65 Mustang. Just backed up the timing a bit. Our GT has never had anything above 87. Maybe that's why the CEL stays on, ha. Maybe our gas is better in Missouri.

round here we only gots 87,89,and 93 never seen 91 beforegot the gt so gotta use the 93 premium and i swear it makes a difference 87 makes the 03 gt run like $h!t

i use the lowest octane..cuz it's the cheapest for my crap sunfire..even if i had a vibe..i'd still use the cheapest..cuz to me gas is gas

Gas is gas like water is water, until you get sick from protozoa and can't stop pooping for 10 days straight.

Quote, originally posted by Raivis »round here we only gots 87,89,and 93 never seen 91 beforegot the gt so gotta use the 93 premium and i swear it makes a difference 87 makes the 03 gt run like $h!tthat would be because you HAVE to run premium in the GT!

Quote, originally posted by ragingfish »that would be because you HAVE to run premium in the GT! You have to run premium in the GT? What?????? That's news to me! Learn somethin' new everyday. Anywho, I'll NEVER run higher than the octane suggested by the manufacturer. When I had the Vibe, I was throwing my money away. I thought it would run better on premium, but in reality had I stuck with the 87 octane the base is supposed to have, I would have been in much better shape. It began to run like crap, got bad mileage, and would really throw a temper tantrum if I chose to run the octane that it actually was supposed to have. I was stuck putting the higher octane crap in there because apparently the car became used to that junk.I just hit 19K in the new car, never ran anything over 87 octane, and guess what... Killer mileage, good power (even considering its low output ) and runs smooth as silk, especially with Chevron. I learned my lesson and have chose to never give this car the "treat" of premium.

Just filled up after first tank of 89. No increase in MPG noted. It did get cold as it should be here in Ohio this week. We will wait fro tank 2 to run through. Mpg should have dropped with the colder temp. We shall see.

Just wondering Is 93 octane with Octane boster good For the Car(03 base)??(went From 91 to 93 cause we moved)

Folks, I really messed up. Put 93 octane in the GT last night by mistake. Hope it don't get used to it.

I used 87 and then 91+a few octane boosters. Using a scan gauge to test everything the MPG stayed exactly the same after testing 2 tanks each.Engine load at full throttle maxed at 80. This is on a base vibe

Quote, originally posted by ColonelPanic »You have to run premium in the GT? What?????? That's news to me! Learn somethin' new everyday. 91 or higher. I run nothing below Sunoco 93 in both vehicles.

After the second tank I got a dec. of about 1mpg. Going back to reg 87.

I use 94 Octane from MOhawk with Ethanol. Its available at a couple of places beside my home so I use that its the same price as Pemium so why not.

I ran regular grade for the first 70,000 miles....I had tried higher octane fuel but didn't notice much difference....around 70,000 miles I tried 93 octane again and could actually notice a performance difference...not a huge difference but just enough to keep putting in 93...

well, i got my car retuned for 90 octane (pump craptacular gas here). it's lacking a lot of power... but he said he tuned it very conservative until i can do some datalogs so he can make sure i don't detonate the car. still plan to use a Torco fuel mixture, but just a 1/4 of a bottle vs 1/3-1/2. the car runs so much smoother on it plus i can feel a lot more oomph and better mpg. and lord knows i need better mpg!

I use 90 octane because of the unichip tune on my car... it seems to respond best with that grade.

I never know what I'm using cause I have no idea what my neighbor buys as I siphon gas outa his car every other night. He has really been *****in' 'bout his gas mileage tho! I told him he needed to get a tune up. Hope his new plugs also fit my Vibe.

Quote, originally posted by jake75 »I never know what I'm using cause I have no idea what my neighbor buys as I siphon gas outa his car every other night. He has really been *****in' 'bout his gas mileage tho! I told him he needed to get a tune up. Hope his new plugs also fit my Vibe.ouch but funny hahawell update, I switched back to 87 octane when I demoded my Vibe but now I'm back to 90 octane in the new car.

Base 1.8 only requires 87 anyway.... You shouldn't ever notice any difference between the grades unless you happen to get a bad batch.....no need for any other octanes in this engine--- just throwing money away!!!!!

Since I just got the car, the manual said 87 is ok, but I usually run 89. As for stations, here in western PA, I try to use Gulf stations. There's few of them left, but it seems like I get better mileage off of Gulf gas. I have also heard that Sheetz gas is horrible. A long story, but I had trouble with their gas in my Storm. I haven't bought any since (and won't!).