Could You Run 91 Octane

[noisia]

my old man is possibily selling his commodore and he's thinking of buying a dead stock r34 gtt. now could he run 91 octane in it? because i doubt he will want to run it on 98 all the time.

cheers guys

[axe s]

I think minimum is 95... thats what they are tuned for in japan...

[noisia]

oh k, so yeah well if there recommended for 95, u could get away with 91 if its just gonna be a cruiser/daily couldnt ya?

[89CAL]

the whole idea of a high octane fuel is so the engine wont detonate on boost. Higher octane fuel burns cooler and faster? (from memory)

the tune is probably run for 95

it would be possible to run 91 i guess but i dont think ud ever be able to hit boost and it would be really unsafe anyway

Edited July 13, 2008 by Boostin96

[noisia]

yeah well thats true, just thought you might be able to get away with it if u running stock boost, stock exhaust and everything

[Kujotk]

r34 still uses an rb25det as does my R33 series 2, i put 91octane in once about 5 months ago when there was a shortage of premium fuel available in NSW, the car did run but not well..... had idle problems and had allot less power and the car never really ran the way it did untill yesturday when i flushed out the throttle body, changed the spark plugs and lifted the idle alittle...... the car can run on 91 but its not recommeded

[Basti]

no you wont. japanese run a higher octane fuel than we do. their premium is 100 or more. 91 on a stock gtt is asking for trouble everytime you hit boost

[adam-__-]

You'll be able to run it on 91 octane fuel. With the car running good or efficiently is a different issue.

Just tell your dad that if he's gonna run it on 91 octane fuel, he risks blowing the motor and he'll get shittier Ks done compared running it on 95 or 98. It seems to work for my parents!

Edited July 13, 2008 by adam-__-

[br3ndan]

If he wants a skyline, he should be prepared to pay for it otherwise its going to cost a alot to fix when things go wrong. They arent cheap cars to run.

At the lowest oct 95. If not oct 98.

Im a uni student and even i pump my skyline with bp ultimate 98 without fail.

just my 2 cents =)

[noisia]

i also always run my car on 98. never 95 cause i start to get ping. i doubt my old man will be getting one then, especially with fuel prices the way they are, tis a pity.

[SHANE666]

if you run 91, ill slap you.

haha

id keep it 95 minimum

[noisia]

lol. i'll be slappin my dad if he doesnt get it

[Kujotk]

i'll slap anyone who uses shell aswell,,,,,, i find it not as good as bp and caltex 98, car runs alittle rougher..... except for shell v power racing but i cannot find it anymore

[teng]

R34 GTT is much newer than R33 GT's and i WILL NEVER run anything that is lower than 97 on it. My B13 uses 92 so if you wanna pump something that uses 91 get a B13 or equivalent. No offense here, just that it's such a waste to ruin a nice RB25DET cause of cheap fuel

AND

On another note, No-one is gonna leave a GTT stock forever

Edited July 13, 2008 by teng

[Kujotk]

true teng,,,, also i only used normal fuel ONCE because there was nothing around and had no choice....lol im an idiot but not stupid..... also dont be a tight ass on fuel,,,, put good stuff 98 oct in it and its usually less than $5 difference per tank..... $5 X 52 weeks is $260 more to use 98 octane than the 91 octane..... compare this to the probs that can be caused by the cheaper fuel..... new engine.... we looking at in the $1000's......

on that note..... what about the 98octane with 10% ethanol blend???? there is romours about ethanol destroying engines but from my understanding there was no proof???? ethanol is a natural octane booster and burns more efficient than conventional petroleum and is about 4 cents per litre cheaper, would there be any probs with that alternative??? the petrol companies say there should be no probs with any jap made car that uses a non carburator engine.....

[RBwhatever]

true teng,,,, also i only used normal fuel ONCE because there was nothing around and had no choice....lol im an idiot but not stupid..... also dont be a tight ass on fuel,,,, put good stuff 98 oct in it and its usually less than $5 difference per tank..... $5 X 52 weeks is $260 more to use 98 octane than the 91 octane..... compare this to the probs that can be caused by the cheaper fuel..... new engine.... we looking at in the $1000's......

on that note..... what about the 98octane with 10% ethanol blend???? there is romours about ethanol destroying engines but from my understanding there was no proof???? ethanol is a natural octane booster and burns more efficient than conventional petroleum and is about 4 cents per litre cheaper, would there be any probs with that alternative??? the petrol companies say there should be no probs with any jap made car that uses a non carburator engine.....

I used just the standard E10 91RON stuff once on a 98RON tune. It was crap, well it drove fine driving normally but once you put it under any kind of moderate load and boost......instant ping. But the cruising economy did well kms wise. I won't be using it anytime again though.

[eMsta]

except for shell v power racing but i cannot find it anymore

thats being phased out

i used 91 ron once in my r33 - big mistake......never went back to that ever.........only use 98 ron now

[arbess]

PING!

yeh use a minimum of 95.

gl hf

[iseekool]

the whole idea of a high octane fuel is so the engine wont detonate on boost. Higher octane fuel burns cooler and faster? (from memory)

the tune is probably run for 95

it would be possible to run 91 i guess but i dont think ud ever be able to hit boost and it would be really unsafe anyway

Higher octane burns slower (i'm not sure if it burns hotter or colder). The reason for pinging is the fuel burns "too fast" - most of the energy in the fuel is depleted well before hitting top dead center - therefore not giving the maximum kick.

That is why the car will ping if the ignition is advanced (fired earlier).

[iseekool]

my old man is possibily selling his commodore and he's thinking of buying a dead stock r34 gtt. now could he run 91 octane in it? because i doubt he will want to run it on 98 all the time.

cheers guys

Not a good idea, the R34 gtt requires 98 as a minimum (even though it says 95 - fuel is variable - always anticipate 2 octane points lower eg. your 95 fuel could go down to 93). 2 main reasons to go 98 - Firstly it is turbo and secondly the RB25DET NEO has higher compression than the previous GTTs.

I own an R34 RB25 non turbo and I found that if I use 95 there is slight pinging on hills and my consumption seems to rise by about 2 liters per 100. I also drive fairly lightly. So I use nothing lower than 98 (unfortunate because of the price of fuel - however it is good insurance against my engine going pop).

It will be worse on a GTT.

At the end of the day buying a GTT and running it on regular 91 is a waste of money, as you will always not want to have it on boost, effectivly having worse performance and economy than a non-turbo model.