98 octane?

[frankyvr4]

hi guys!just wanting to know if there is any mods that needs to be made to run 98 octane fuel and what are the pros and cons?

[Nick Mann]

?

As compared to what?

The standard engine/ECU is expecting high octane fuel. These cars can suffer from knock on low octane fuel, leading to timing being pulled from the ECU and a related loss of power. The ECU will put the timing back to normal after spirited driving without any knock. How much timing gets pulled (and how much power you lose) is dependant on the level of knock present. Please note that the car does this to protect itself, as knock is an engine killer. The only sensible advice is to always run your car on high octane fuel to avoid knock as much as possible.

[Subaru ETA]

98 is the highest octane we can get in NZ so run on that.

Interesting fact - the fuel flap on my airtrek says to run it on 100 octane!!

[jjayokocha]

In NI the best fuel i can get is BP Ultimate which is 97 octane & the garage beside me their pump broke the other day

[Ryan]

98 is the highest octane we can get in NZ so run on that.

Apart from Gull Force Pro which admittedly can't be used in all cars but it is available from the pump, only wish that we could use it

[OnBoost!]

I have been using Shell V-Power for the last few weeks,it's a bit cheaper than BP's 98,to me there is no difference in power....

[Gly]

i can feel the power loss using 95, but thats at 13psi,
at stock boost cant tell the diff between 95 and 98,

so guess its relative to how your cars tuned, and your foot,

for the most part i run bp98,
and gull force 10, (runs best on this, but the eth mix makes it drink more)

[Nick Mann]

I've seen standard cars knock like a git on 95. Counts of 15! I guess it is dependant on a few things. It will only happen on high throttle though, so if you are never going to use the power, then put what you want in. (Although, TBH, at that point buy a lower powered car!)

[chris g]

To use 98 ron, have more money in your pocket, get a better paid job, sell a kidney, put the kids into chimney sweeping...

[Wodjno]

Been running mine on Supermarket 95 run for the past few months But i have mostly been pootling around and Mrs Wodj has been using it to run back and forth to work. MPG has been pretty good on the lower octane stuff But the odd occasion that i have "Had" to give it some beans, i have noticed how reluctant the car has been to rev freely(At WOT) past 5500 to 7000rpm + ! I've found myself changing up in 1st and 2nd at 5000rpm as the cars hesitancy above this level doesn't feel good at all. I filled up with Tesco Monentum 99 yesterday and the difference in the higher rev range has been transformed. The Needle on the Rev counter now races round to 7000rpm + with no hesitaition whatsoever, and feels like it would go to 8k with no bother either This would suggest as already stated, that the timing is being pulled back severely on the lower octane fuel, as knock is being sensed. And this is why it doesn't rev freely above 5500rpm at WOT.
Run your car on the highest Octane fuel possible, especially if you are going to be giving it plenty of beans. As Nick says Knock is and engine killer"

[frankyvr4]

awsome!thanks alot guys!only reason i asked is mine has a sticker in the flap saying only 91 octane.

[Wodjno]

awsome!thanks alot guys!only reason i asked is mine has a sticker in the flap saying only 91 octane.

That could be a Mon sticker and not a Ron sticker ?

[wintertidenz]

Rip that sticker off - it's definitely wrong.

[lateshow]

here in finland we get 95E10 which has 10% alcohol, wouldn't even try. Then there's the 98E5 which is 98 octane fuel with 5% alcohol, I'm mainly driving with that now. Then we have also the V-Power that Shell states to have 99.x octane and yes, i get less knock with that one. Nothing has actually changed since i've tuned this car. It can have the same amount of advance with same petrol. With 98E5 i can't use the original 160 column as I can with the V-Power. However V-power is much more expensive, harder to get and fuel consumption stays the same. So let it knock! I dont care anymore, with stock turbos the car is damn slow anyway.

[Niran]

Question, I have been pumping Mobil fuel (97.5) as its a bit cheaper. Do you think i should just pump BP 98 instead? And bear the costs?

[Badger_01]

Question, I have been pumping Mobil fuel (97.5) as its a bit cheaper. Do you think i should just pump BP 98 instead? And bear the costs?

Yup do it I do lol

Plus if you're a AA member you got 4c discount when you spend over $40 for fuel

[Gly]

at the end of the day, its only a few cents per liter, and at 55L (rated tank size), the 5-10c difference is $2.75 to $5.50,
not much of a saving IMO cant even buy a pint for that in a auckland pub

[Niran]

Sweet! Cheers guys!

[wintertidenz]

Ryan did a comparison a while back - BP vs Mobil fuel. IIRC BP was the winner as it was slightly more economical and at WOT the ECU's octane rating dropped less (probably due to less knock).

I've always found that the car runs better on the BP 98 octane anyway, and as Carsten said, it's only a few cents more (although with an AA Smartfuel card it evens out).

[Ryan]

http://www.clubvr4.com/forum/showthr...us+bp+ultimate