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Discussion Starter · #1 ·
After a couple days of looking around I heard that there was a gas station in Ottawa that sells 98 octane pump gas as well as 110 octane race gas (in 20L cans). As a result, I got really excited and had to go get some. I decided that i'd put 35$ worth of 98 octane in the car to see if I could tell a difference from the 94 octane that I filled up with previously from Petro-Canada.

I went there this afternoon and to my surprise there was one dedicated pump that only pumped out the 98, so I put about 35$ in to see if I could tell a difference. I drove the car for 5 mins to find a bit of open road and then did some testing. I felt that the car definitely pulls a fair bit harder between 3500 and 6500 rpm. I'm not sure if its just in my head but I could definitely feel a difference.

I was wondering if any of you have ever filled up with 98 octane for spirited city driving or is it just a waste as it does cost 2.90$/L which works out to about 11 bucks a gallon for all my friends in the states
. Honestly, I think thats a bit too expensive but i'd like to know what you guys think -- is it worth the extra cost?
 

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Discussion Starter · #3 ·
I spent hours trying to find a location which sold it! But its super super expensive. 11 bucks a gallon is insane!
 

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The 98 probably isn't leaded, while the 110 probably is. Don't use LEADED fuel in your car. It tends to foul your spark-plugs. It might be worthwhile to ask about this (leaded or un-leaded) at the gas station...

Alexd
 

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Unless your car was literally running on fumes...if you just put 3 gallons of 98 in your tank, on top of whatever was in there already, you didn't achieve much of a test. I'm sure you don't want to hear this, but I think any "seat-of-the-pants" testing results were placebo effect.

Alexd
 

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Discussion Starter · #6 ·
the 98 is unleaded, i asked them. Didn't ask about the 110 as I didnt buy any this time. But I will if/when I buy some.
 

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Discussion Starter · #7 ·
Unless your car was literally running on fumes...if you just put 3 gallons of 98 in your tank,on top of whatever was in there already, you didn't achieve much of a test. I'm sure you don't want to hear this, but I think any "seat-of-the-pants" testing results were placebo effect.

Alexd
I got it down to the point where the estimated range was 8 miles.
 

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Discussion Starter · #8 ·
Unless your car was literally running on fumes...if you just put 3 gallons of 98 in your tank, on top of whatever was in there already, you didn't achieve much of a test. I'm sure you don't want to hear this, but I think any "seat-of-the-pants" testing results were placebo effect.

Alexd
+ im kinda happy you said it cuz it may stop me from spending 11 bucks per gallon lol
 

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I got it down to the point where the estimated range was 8 miles.
OK...then you're smart, and the test made more sense.


Alexd
 

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Just found 100 oct at the pump in socal. I mixed it to get 94, since our norml pump is 91 here.

You likely had a power decrease due to slower flame propagation, unless you were knocking to the point of where the ecu was pulling timing with the other fuel. Assuming you are talking r+m/2 octane and not RON octane...
 

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Discussion Starter · #11 ·
yeah it was a little frightening to see this so i was going up and down on the road lol.
 

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Discussion Starter · #12 ·
Just found 100 oct at the pump in socal. I mixed it to get 94, since our norml pump is 91 here.

You likely had a power decrease due to slower flame propagation, unless you were knocking to the point of where the ecu was pulling timing with the other fuel. Assuming you are talking r+m/2 octane and not RON octane...
Do you think the ecu already learnt the fuel type as the 94 from petro can was my first fill up.
 

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Just found 100 oct at the pump in socal. I mixed it to get 94, since our norml pump is 91 here.

You likely had a power decrease due to slower flame propagation, unless you were knocking to the point of where the ecu was pulling timing with the other fuel. Assuming you are talking r+m/2 octane and not RON octane...
I know what you're saying...but I doubt that (decrease).

It is known with dynos that 93 can show a small HP increase over 91 for instance, and so on. The dynamic ECU adjusts for greater timing (to a point) when higher octane is being burned. It could further be argued that the higher octane gas probably decreases the AF ratio slightly, which in turn probably (slightly) adds power in a stock tuned engine.

Alexd
 

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Do you think the ecu already learnt the fuel type as the 94 from petro can was my first fill up.
Someone can correct me if I'm wrong...but I don't think the ECU stores info like that; instead reacting moment to moment with what it "senses" (with acceptable micro-knock).

Alexd
 

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Discussion Starter · #15 ·
Someone can correct me if I'm wrong...but I don't think the ECU stores info like that; instead reacting moment to moment with what it "senses" (with acceptable micro-knock).

Alexd
Ahh kk, i was under the impression it learnt the fuel type and then checked periodically for changes. But it makes more sense if its actively reacting
 

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Discussion Starter · #17 ·

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E85 is where it's at
There's no doubt that you can tune for more power with E-85, compared to 100+ octane gasoline.

But, there are practical considerations; it's not for everyone:

1) Is it available and/or at a good price, where you live?

2) You will need an increase over stock with at least injectors and fuel pumps...and a tune for it.

3) There MAY be increased problems with starting in very cold weather.

4) Your gas station may advertise (on a label on the pump) that the E85 may be ranging between a lower limit of 70%. This isn't so good if you're "tuned to the teeth" for E85.

But again...more power...and probably cleaner/less smells (if you don't have cats). It's good to consider all aspects...

Alexd
 

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Discussion Starter · #19 ·
There's no doubt that you can tune for more power with E-85, compared to 100+ octane gasoline.

But, there are practical considerations; it's not for everyone:

1) Is it available and/or at a good price, where you live?

2) You will need an increase over stock with at least injectors and fuel pumps...and a tune for it.

3) There MAY be increased problems with starting in very cold weather.

4) Your gas station may advertise (on a label on the pump) that the E85 may be ranging between a lower limit of 70%. This isn't so good if you're "tuned to the teeth" for E85.

But again...more power...and probably cleaner/less smells (if you don't have cats). It's good to consider all aspects...

Alexd
yeah, im planning on keeping it stock with the exception of the midpipe i bought for a while at least.
 
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