Anyone mix 89 and 93 octane?

[Grimey]

Everytime I fill my tank, I use 93 (for a full empty tank).

Some mornings on my way to work with like 90 miles into the full tank, I top it off with 89. Since the minimum octane rating that the Si must be filled with is 91, I figure it's alright.

The majority of the fuel is still 93, so it's not really half-half. For someone that doesn't drive much, it may seem pointless... but for someone that drives 80 miles a day to work, the .20 difference starts to add up eventually.

Thoughts?

[bilzfan]

I do the same thing, onec in a while. I've got a friend who's Dad owned a gas station. My friend said that the mid grades used to be blends of the Higher and lower octanes that were done at the pump in the 60's. I can't see anything wrong with blending down to around 91. My car doesn't seem to run any different when I blend.

[Grimey]

Originally Posted by bilzfan

I do the same thing, onec in a while. I've got a friend who's Dad owned a gas station. My friend said that the mid grades used to be blends of the Higher and lower octanes that were done at the pump in the 60's. I can't see anything wrong with blending down to around 91. My car doesn't seem to run any different when I blend.

I haven't noticed anything different either- performance wise or MPG.

Like I said, I'll top it off once, maybe twice with 89... but that's about it. The majority of the tank is still 93. Also, I use the same gas at the same exact gas station when I do this. I never mix brands.

[Leonard1818]

I've always wondered if 1/2 part 93 + 1/2 part 89 = full tank 91.... (since most places around me don't carry 91)

[rsm1113]

I've done it as well, no changes in performance, sound, or MPG. You are all good.

[ygoslo]

this is great to know,and even better if gas hits 4 bucks this summer

[icen]

any knocks or ping?
if not, i's ok

[Phalanx]

Originally Posted by Leonard1818

I've always wondered if 1/2 part 93 + 1/2 part 89 = full tank 91.... (since most places around me don't carry 91)

I was wondering the same last week. I actually put 89 in my car without realizing it. Every pump I go to is the same layout... 87 89 93 (in that order)... so I just grab the rightmost one and go at it.

Well, this one station I stopped at... i didnt look until i was almost done filling, just to see how much the gas was, and the layout was ... 87 93 89 ... i was like 'wtf? i just put 89 in' ... figured it didnt matter much and I didnt notice any difference in that tank.

Itd be nice to know if it really works like that (mixing 89/93 to get 91).... but somehow I doubt it does work like that.

Originally Posted by icen

any knocks or ping?
if not, i's ok

Thats what I'd be remotely concerned about. But I dont know the real answer.

[Grimey]

Originally Posted by icen

any knocks or ping?
if not, i's ok

Absolutely none, and I've done it a few times.

No changes in performance, or MPG. But like I've said, the largest ratio I've prolly pushed is 3/4 93, 1/4 89. I've never split it.

I wouldn't recommend mixing brands either, if you are gonna do it you should probably use the same brand gas to ensure the octane ratings are the same.

[Grimey]

I just ran some numbers...

Lets say you fill the tank to 13.5 gallons (and yes I've put that much in already), and use the prices I filled up at this morning--$3.19 89, and $3.35 93.

If you split it up, that's 6.75 gallons for each 89 & 93.

The total price for the 6.75 gallons of 89 is $21.53.
The total price for the 6.75 gallons of 93 is $22.61, for a total price of $44.14.

If you were to use all 93, the total cost would be $45.23. Your total savings for that fill would be $1.09 for that tank.

Now $1.09 may not seem like a lot, but if you plow through about a tank or more a week that is a savings of $56-$60 a year.

Just some food for thought.

[07BlakBlak]

$56-$60 a year in savings? Are you seriously worrying about that......if you are that concerned you should have spent the time you just used working up those calculations to find a new job....making more money. $56 will be the least of your concerns.

[Grimey]

Originally Posted by 07BlakBlak

$56-$60 a year in savings? Are you seriously worrying about that......if you are that concerned you should have spent the time you just used working up those calculations to find a new job....making more money. $56 will be the least of your concerns.

I just figured I'd run some numbers to see what it'd cost/change

I make more then enough

[7002iSciviC]

ummmmmmm i dont think mixing gas octane is a great idea nor putting octane 89 on your Si. Im pretty sure that mixing 89 with 93 would result 91, i dont think it works like that. but for one thing dont do it i mean it doesn't do anything to your car FOR NOW who knows whats going to happen down the road. i mean common why would honda advise to use only octane 91 for the Si ? theres gotta be a good reason for it, they didnt say you cant use 89 but they require you to put 91. so i wont put 89 on my si. its just me but you know sometimes its better to have peace of mind than having few cents.

[habitat]

You guys that have 93 octane are too spoiled... I would kill for 93 octane, in CA we only get 91!!!

[rob76]

You bought a gas guzzling sports car to commute with and you're worried about $1 a tank? Oy Vey!

[geffsi111]

why don't you trade your Si for a Regular Civic (lx or ex)...this way you will be able to save more money (less octane and higher mpg)...just my thoughts...

[OhondaU]

The Si...a gas GUZZLER?! Even when I give it some really good sprited driving mixed with my usual commutes to work the Si routinely gives me at LEAST 25-27mpg. On a long highway trip i can get 33mpg just cruising. Compare that to my non-guzzling non-sports car Subaru Outback which could only cough up 27mpg cruising on the highway.

Gas Guzzling Si....! idiot....

[OrdnanceMarine]

Originally Posted by habitat

You guys that have 93 octane are too spoiled... I would kill for 93 octane, in CA we only get 91!!!

I fill up at my local VP Racing where they sell 87/89/91/95/100. Last time I remember checking, 95 was something like $1/gallon above 91 and 100 was in the $5.XX/gallon! Friend of mine forgot to check until he had filled up the tank (kind of like Phalanx mentioned, he was used to the position) and he had dumped 95 in a rental car he was returning that should have seen 87. $15 mistake, oh well!

Gotta get out of that granola eatin', Birkenstock wearin', carbon-credit buying bay area and come out to the gun-totin', gas-burnin', high-octane part of California!

[Grimey]

Originally Posted by OhondaU

The Si...a gas GUZZLER?! Even when I give it some really good sprited driving mixed with my usual commutes to work the Si routinely gives me at LEAST 25-27mpg. On a long highway trip i can get 33mpg just cruising. Compare that to my non-guzzling non-sports car Subaru Outback which could only cough up 27mpg cruising on the highway.

Gas Guzzling Si....! idiot....

When did anyone in the entirety of this thread call the Si a gas guzzler?

At no point in this thread did I even once complain about gas prices or the fuel economy of the Si, I was simply making an obersvation and asking a question.

[Phalanx]

Originally Posted by Grimey

When did anyone in the entirety of this thread call the Si a gas guzzler?

See below...

Originally Posted by rob76

You bought a gas guzzling sports car to commute with and you're worried about $1 a tank? Oy Vey!