98 Octane fuel...

[Guest]

Just wondered if any members can tell me how their fuel consumption figures compare to using 95 Octanve fuel? Been told to change to 98 and have read various reports that say you get better fuel consumption, although higher price, lol.

[Guest boostcut]

in all the cars i have put it in, the fuel price is offset to the amount less fuel it uses. if you know what i mean. because i dont.

[aim]

it depends what it's tuned for, AFAIK, cars tuned for 91 will get worse fuel consumption on 98. The main reason for using a higher octane is to prevent det under boost.

[Guest]

 aim said:

it depends what it's tuned for, AFAIK, cars tuned for 91 will get worse fuel consumption on 98. The main reason for using a higher octane is to prevent det under boost.

I am presuming my B4 has been running on 95 Octane since it has been in the country. My mechanic drove it and said that it was 'pinking' under boost. He said I should be running 98. Just wondered what this fuel was like as I have heard that the Gull fuel gives less fuel economy...who knows...

[swiftbrad]

avoid Gull

[Koom]

Can't say much about my Subaru's as I have only used 95 once and it didn't feel right (my RS is a bit tempremental though) but back in the day I had an old Ford Laser that was cheaper to run on 98 than 95 or 91 as its consumption improved that much. Which is the same as what Boostcut thinks he means but isn't sure about, from as much as I can tell about what he means haha.

The Gull stuff is 10% ethanol which improves resistance to det but "could" be the cause of worsened fuel economy. Depends what the ECU wants to do with it though. i.e. If its pulled timing and needs to re-learn.

[Koom]

 swiftbrad said:

avoid Gull

Why?

[aim]

pinking/det/knocking whatever you wanna call it. It's bad, and running a higher octane reduces the chances.

[driftrex]

 swiftbrad said:

avoid Gull

yea why, i use nothing but in my turbo subaru.

[Koom]

 driftrex']

[quote name='swiftbrad said:

avoid Gull

/quote]

yea why, i use nothing but in my turbo subaru.

I would too if only they had Gull down in the backwards south......

[Guest]

What about 98 in the non turbo EJ20's? better fuel economy?

[Koom]

 DGM said:

What about 98 in the non turbo EJ20's? better fuel economy?

Possibly. Worked in my old sh**box ford. Why don't you run three or four tanks of 98 through it and measure how many kms you get out of a tank? Only way to tell if it'll help your car or not.

[Guest]

 Koom']

[quote name='DGM said:

What about 98 in the non turbo EJ20's? better fuel economy?

/quote]

Possibly. Worked in my old sh**box ford. Why don't you run three or four tanks of 98 through it and measure how many kms you get out of a tank? Only way to tell if it'll help your car or not.

I'll try that, I've only had the car for 2 weeks so im still on my first tank.. i'll use 98 next time to see if I get any more km's

[Koom]

To get a decent test you'd need to run a few tanks of each through the car in succession. Swapping grades of fuel each time you fill up won't give a very good indication of how the car responds to each fuel cause the ECU takes time to respond (if at all) among other factors like weather, driving style etc etc.

[Guest boostin]

 Madazj']

[quote name='aim said:

it depends what it's tuned for, AFAIK, cars tuned for 91 will get worse fuel consumption on 98. The main reason for using a higher octane is to prevent det under boost.

/quote]

I am presuming my B4 has been running on 95 Octane since it has been in the country. My mechanic drove it and said that it was 'pinking' under boost. He said I should be running 98. Just wondered what this fuel was like as I have heard that the Gull fuel gives less fuel economy...who knows...

B4's and the GTB wagons detonate on 98 too. It's just how they are. Give it a good dose of Subaru upper engine cleaner to clean out all the carbon build up. A new air flow meter often helps too.

[EJ20T]

 aim']

it depends what it's tuned for, AFAIK, cars tuned for 91 will get worse fuel consumption on 98. The main reason for using a higher octane is to prevent det under boost.

No cars tuned for 91 will not get worse consumption on a higher octane, they just will see no benefit

avoid Gull

Why?

because JDM subarus arnt ethanol compatible, the rubber hoses arnt ethanol safe and may swell and split, also in old cars it strips all the varnish and build up and it blocks filters and injectors.

[quote name='aim said:

it depends what it's tuned for, AFAIK, cars tuned for 91 will get worse fuel consumption on 98. The main reason for using a higher octane is to prevent det under boost.

/quote]

I am presuming my B4 has been running on 95 Octane since it has been in the country. My mechanic drove it and said that it was 'pinking' under boost. He said I should be running 98. Just wondered what this fuel was like as I have heard that the Gull fuel gives less fuel economy...who knows...

the amount of det on 95 in our model is terrible, 98 is a absolute must, it allows the ecu to run the most ignition advance, making it the most efficient, ive got a best figure of 8L/100 km using 98.

[Koom]

 EJ20T']

[quote name='swiftbrad said:

avoid Gull

/quote]

Why?

because JDM subarus arnt ethanol compatible, the rubber hoses arnt ethanol safe and may swell and split, also in old cars it strips all the varnish and build up and it blocks filters and injectors.

But NZDM ones are? They have NZDM fuel lines at the factory? I still don't buy that bit of PR.

The varnish bit may have some backing but I've had fuel lines swell and split on 98. Not really scared of it being more common with E10 personally, but I want it for the performance benefits.

[sultan]

i have seen approx 10% better milage to the dollar running 98 on my 4age, and dead even to the dollar on my 1jz. i've only ever run 98 on my wrx as its dyno tuned for it. i imagine like the 4age it would be more economical

[EJ20T]

its only AUSDM models rated for E10 or greater, hence any of the JDM NZ new cars arnt rated for it (ala NZ new sti pre ver10, all turbo legacys pre my07? etc) any model that was australian available is fine.

[Johnnynz]

I have been running my WRX on Gull 98 since introduced (a yearish) and over 20,000 KM without issue.

Not saying its safe, just saying.

[driftrex]

ive run gull 98 in my 96 wrx for most of the 60-70,000kms since ive owned it, unless im in a town that doesnt have one, so how come my fuel lines are still sweet? i have changed the engine bay lines only because of doing split fuel rails but i mean the lines by the tank.

i wont be changing away from gull seen as i haven't seen any negative affects.

[Guest]

Since buying my GT-B TT I've only ever used 98 and achieve about 550km to a tank, so a little bit shy of 10km/Litre. However, when I tried 95 in an emergency, 10L got me 4km. Sucked ass. No power on take off, couldnt rev too high as it would pre detonate, stalled all the damned time. Was a stink affair.

[Guest]

ps, better mention that I run it exclusively on BP ultimate.

[Guest]

 EJ20T said:

its only AUSDM models rated for E10 or greater, hence any of the JDM NZ new cars arnt rated for it (ala NZ new sti pre ver10, all turbo legacys pre my07? etc) any model that was australian available is fine.

The JDM cars are not rated for it because they have never been tested for more than 3% back when they were made.

Subaru NZ or Japan have done no tests with e10 on older cars and they have no intention of doing any as its easier and cheaper not to.

So sure its not rated but that doesn't mean its not ok.

[Oesnam]

 Heroes Legend said:

Since buying my GT-B TT I've only ever used 98 and achieve about 550km to a tank, so a little bit shy of 10km/Litre. However, when I tried 95 in an emergency, 10L got me 4km. Sucked ass. No power on take off, couldnt rev too high as it would pre detonate, stalled all the damned time. Was a stink affair.

All these high mileage's everyone achieves with TT GT-B's and B4's are starting to irritate me as I only manage to get max and i mean max of about 440-460km on a full tank. Thats with no boosting at all to check the economy. Maybe mine is running too rich or something. Or maybe because its a rev.B?