..Mark..

Where are you guys buying 91 octane. I have been putting 93 in but w/ gas getting pricey i want to shift to 91.

Discuss..

AcuraVic

I have not found 91 in the A. I started mixing 89 and 93 6 months ago. The TL loves the mix. I used to use 93 (from quick trip only) and my engine idles smoother with the 89/93 mix compaired to the 93 only.

jumbosizeme79

havent seen 91 in atlanta either... 93 all the way, dont ruin your cars engine. then agian gas prices are raising like a *****

don5504

Are there many stations that carry 91oct here in GA? I usually see just 87, 89, 93, but I think I use to remember seeing 91oct. Anyways if your car runs well off of 91oct (or any lower grade) and doesn't knock or ping I would do it. You would actually be increasing the power your engine is capable of and saving yourself money at the same time. I am going to be hooking up my OTC genisys just to monitor knock and timing to see if it is possible to run a lower grade gasoline than 93.

D

phee

iTrader: (5)

keep us updated on this^^ and 91 isnt available in our region.

don5504

Also not that any of you would drive 50miles to save 10cents/gal but here is a website about what stations in GA have the best and worst gas prices. Searches can be done by location and grade as well as diesel.

http://www.georgiagasprices.com/

D

vinnier6

iTrader: (1)

octane is a regional thing as far as premium goes...some areas have 93 while others have 91...but usually not both....i have seen it in rare cases...

vinnier6

iTrader: (1)

i want what your smoking.....

cleex024

yeah me too

cleex024

how is it even possible to increase power by going to lower octane gas?

AcuraVic

I know you are trying to be funny, but what I said is a fact.

AcuraVic

Same to you...

..Mark..

Back it up w/ a link from a reputable source then.

Bearcat94

Higher Octane = Harder to ignite. Lower Octane = Easier to ignite.

If you run the Octane too low the compression and temps in the cylinder can cause ignition to early, pre-detonation and/or knock/ping.

If you run the Octane too high, the fuel/air mixture may ignite slower or incompletely.

So, to get the "correct" timing and burn Acura says run 91 Octane. Lower compression engines would be able to get max burn/power from lower Octane fuel.

don5504

Thank you for that and to expand upon what Bearcat has already mentioned....

Ounce for ounce volume for volume lower grade gas has more BTU's than their higher octane counterpart. See the thing is the stuff that increases your octane rating ends up diluting your actual gas. How hard something is to combust has no direct relationship with how much potential energy it contains.

Toulene has an octane rating of somewhere around 110 or so. And it is flamable. But due to chemistry and science releases less engery when ignited.

D

dejavecu

I cannot dispute this observation nor can any anyone else but this observation does run contrary to the established use of octane rating. The octane number, in the US, refers to how resistant the fuel is to autoignition (ignition without spark, uncontrolled by the engine) and therefore knock. A higher number means less knock.
This number may be somewhat variable due to the mixing practices of the company as in some areas you can blend your own octane rating at the pump. This variances at the fuel station could explain Acuravic's observation as the fuel he is combining may be more mixable, although, lowering the fuel's octane number should not produce more favorable results. While the difference between 91 and 93 octane may be superfluous in some engines and climates, 93 should not produce a worse result.
I have not encountered 91 in Georgia in my many years driving in the state; the octane available at the pump are dependant on many things including the altitude of the area in which the gas was purchased.
By and large, self-mixing (combining fixed octane ratings) at the pump does not produce a unilateral product. Different octane rating gas does not share the same density and therefore your vehicle may be burning 93 and then burn a "pocket" of 89 which any ECU would have a hard time countering.
Also, consider this little-discussed problem: when you are pumping 93 gas into your car, there will be a residual amount pumped into your tank left over from the person before you e.g. you could be pumping in half a gallon of 87 instead of 93. The amount of this residual gas would be also dependant on the pumping mechanism of the gas station.

Sorry Bearcat, I did not mean to duplicate your point. Blame my hanging browser for my reaction time in posting.

1995hoo

See if there is a Sunoco in your area. The ones here in the DC area sell 91 octane. Here's their site with a station locator:

http://www.sunocoinc.com/site

There's no reason not to use 91 if you find it. It won't save you very much money (usually about a 2¢ per gallon difference from 93), but it won't do any harm. The TL's engine is designed to run on 91 or higher octane because 91 is the highest octane available in most western states. I was suspicious at first (as "jumbosizeme79" appears to be), but I did a bunch of research and asked some mechanics and was universally told there should be no problems. I was concerned that the car would have a "tolerance" or some such thing whereby it would be used to 93 or higher octane and would need to keep using that. (My 1982 Accord never ran well on regular 87 octane, so I used 92 octane, which was then the highest available. After they phased out leaded gas and introduced 89, I tried that, but the car didn't seem to like it. Hence why I thought there might be an issue.) Anyway, I use both 93 and 91 and I notice no difference between the two; I've also noticed no difference when I've used 94, which is no longer available here.

berzerker

but ALL prices are going up across the board, from 87 to 89 to 91/93 - so is it really worth worrying about trying to save that kinda money by switching to lower grade gas and possibly damaging your car, getting less performance, and maybe less mpg's anway? (more so for people trying 89 rather than 91)

think of it this way: if you use 2000 gallons of gas a year, and buy gas at these prices, even if you switched to the lowest grade available, you're not saving a whole lot of money

87 @ 3.90 = $7800 per year

89 @ 4.00 = $8000 per year

91/93 @ 4.10 = $8200 per year

so for the whole year of using lowest grade gas, you save maybe 400 bucks or about $33 per month - a dollar a day? Is it worth the potential problems really? I say no. just my

AcuraVic

No need. You be the judge for yourself. Next fill up, put six gallons of 89 and six gallons of 93. Then, give you opinion on your cars performance/smoothness.
If you don't notice an improvement, then I'll except that my car may be the exception rather than the rule. My reasoning is that the computer is designed for optimum performance using 91 octane, and the 89/93 mix is getting close to the 91 octane.
Mixing the gas was an accident and not intentional. Months ago, I had a half tank of 93 and the station had the premium pumps turned off. I put 89 in and the car ran smoother the next day.

Oh, and I have a 04/TL Auto.

don5504

I believe our cars are actually setup to run on 91oct. So I don't believe running a higher octane will increase performance unless tuned for that octane unless on 91oct its running on the ragged edge of knock/preignition then it could increase performance due to less timing being pulled. But I do believe it can certainly reduce performance if using a lesser grade of gas than 91oct. Because I assume that on 91oct its running like it is suppose to and with a lesser octane gas more timing will be pulled.

Also I am unsure if everyone in here is from GA/ATL but the price differences between the grades have been more like $.20 instead of $.10 so you can double those savings figures.

And there are no potential problems really. Even on the acura website it states you can use gas of a lower octane rating than 91 just with reduced performance mentioned nothing about possible damage. Now if you are not stock and have mods out the ass that is a complete different story.

D

AcuraVic

http://www.gnttype.org/techarea/misc/Octanemix.html

there is a spreadsheet on the page that will calculate you mixed octane level.
I do 6 gallons of 89 and six gallons of 93.

AcuraVic

another link...

http://www.repairfaq.org/filipg/AUTO...l#GASOLINE_016

AcuraVic

Another link...
http://members.cox.net/ftraycing/octanecalc.shtml

wgambella

I filled up this morning in Suwanee.
Reg was 3.99
Mid Grade was 4.09
Super was 4.19

My buddies father owns an Acura dealership in Tennessee and said dont worry about putting 87, or 91 in our cars. The timing for firing will automatically adjust and the slight difference in raw HP wont be detectable without putting it on a dyno. He also said there would not be any damage to the vehicle whatsoever.

AcuraVic

So, in my opinion, using my car as a subject and using the info I found on the web,
if you mix equal gallons of 89 and 93 octane you will get 91. Our cars are tuned to run on 91 (my car being the 3.2 engine).
If I buy 12 gallons of 93 at $4.19 the cost will be $50.28.
If I buy 6 gallonsof 89 at 4.09 ($24.54) and six gallons of 93 at 4.19 ($25.14) the cost will be $49.68. I use 12 gallons as a measure because I rarely put more that 13 gallons at fill up.

Using this method I get 91 octane and pay $4.14 a gallon at todays prices verses $4.19 per gallon.
I'm pumping twice at every fill up but I've got more time than money!!

AcuraVic

Whats the name of the dealership ? My brother and sister both have 04/TLs and they live in Nashville.

berzerker

you could double those figures, but what about less gas mileage with lower grade fuel - wouldn't you that factor into the equation of savings?

I was reading this link below. So each of these guys in incorrect in their posts about not using lower octane? I'm just curious as I've always heard you COULD do it, as you say it's on the acura site, but didn't want to for very long-or at all for loss of performance/mileage or potential for eventual damage. Did the acura site say if you could run it long term with no negative effects? or just something that was to be done on as needed basis? http://www.hondacarforum.com/acura-t...ctane-due.html

wgambella

My buddies fathers Acura dealership is in Indiana, not Tennessee.

Ed Martin Acura

don5504

You made me check up on it a little more. I looked in the owners manual and it confirms what you say. That regular gas should only temporarily be used. While this is in the literature I wonder if that is some sort of legal cover my butt type thing. But I still plan on monitoring the effects of a lower grade than 91 with my OTC Genisys. If I can run 89oct and via engine monitoring see no ill effects I might continue. But I haven't even started any of it yet considering I just though about doing it today. So until then I would recommend they stick with what the book says.

D

TL1999

you can go to any RACETRAC gas station where they sell 92, i think....

I use 93 and it is hurting my bank account...

ggesq

iTrader: (1)

crap- another one of these threads

To the OP- if you want to continue this discussion, do it in Car Talk or Ramblings i.e. where to buy 91 octane gas in Georgia.