RaZe-=Buzz=-

Hmmm...food for thought indeed.

Ive never noticed any unusual behaviour with 95ron, its always run smoothly and consistently since we got it, but like I said b4 its just an old my96, one of the 208's I believe, so Ive got pretty much the plainest turbo going with the standard air filter and exhaust etc.. However, in the interests of fuel economy Im gonna try SUL. Hell! Maybe even go search out some Optimax and see what if any difference it makes for a month or two, without changing maps or ecu's or re-configuring the forward sensor array etc etc *insert techie gobbledigook here*

Oh, and Mr. H - I feel like a newbie sometimes when I read threads and can only understand one word in three, and have to ask what on earth its all about I wont go NEAR the ICE forum or tech forums..its all made up I tell ya!

[Edited by RaZe-=Buzz=- - 7/1/2002 9:45:52 AM]

PSI3

I noticed today that on the fuel filler cover it says to use only 98 RON fuel, Does anyone use a lesser rated fuel with no apparent problems. In the past in my MY01 i got caught a couple of times and had to use normal unleaded rather than Optimax, but looks like this will not be possible with the STi unless i use octane booster???.

Any other unleaded 98 RON other than Optimax?

my STi is from a official UK Subaru dealer.

simon

DJB

It says on the Subaru website (http://www.subaru.co.uk/index2.htm) that 95 RON is ok for the STi Type UK. I never anything other than Optimax or SUL.

D.

gareth60

I'm using 95 Ron fuel. I guess over the next few years, super will start disappearing from the petrol stations.

Gareth.

DJB

Not sure if I agree. SUL is now if anything more readily available than it was 2 years ago, so there must be a continuing demand. Why would Shell bother to develop Optimax if everybody thought that 95 RON was ok.

Personally I think that they should phase out 95 RON.

D.

johnfelstead

i wouldnt run an STi Type UK on 95 ron, no thankyou! Det city!

bug-eyed wonder

I saw a PD STI filling up with NUL the other day!
The nearest SUL was only 1/4 mile away. Since using SUL in my WRX I wouldn't go back.

SiCotty

It says on the fuel filler cap of my MY00 to fill up with 98RON only.

Si

SCOOBERATORS

Use Optimax mate with booster if poss 100 ron

korky

For the difference in price between unleaded and super unleaded you might as well pay the extra and get the best performance out of your car - let's face it if we are worried about £2.00 a tank then why run a scooby when a diesel Passat gives 50MPG with half the insurance costs?

Also, I understand that scoobies run better on SUL and get better MPG therefore using it could actually save you money.

There's food for thought!

Korky

gareth60

Hmmm,

Yes, I agree to an extent, but one of the plus points about buying a uk spec car is that you can run in on regular petrol. I used to run my MY99 turbo on 97Ron only for 2 years. I then got fed up with having to wait ages to fill up because the only pump was also connected to the diesel pump at my nearest petrol station and it was always "white van man's" turn to put £70 of diesel in..

I've only filled up once in my Sti7 so far and I must admit I may start using 97Ron again, i'll see if Sainburys have added any more pumps....

Regards
Gareth.

integra

In Italy I only use Shell V-power 99 ron! FEDE

RaZe-=Buzz=-

Sad newbie type question here, but thin k about this before you slag me off...How did YOU find out? Did someone tell you?

WTF is this Optimax stuff? Is it some fancy petrol that only Shell garages sell? Do they sell it at all their stations? And how is it diff to SUL that everyone else sells?

I run an my96 UK turbo and its totally standard. Its had about 3 tanks of SUL since we bought it and runs fine on normal as far as I can tell. Maybe if it was tuned to booogery SUL would be required. But is it really worth looking out for Optimax?

Thanx for the none-slagging, none "newbie scum" replies (if any )

TonyBurns

iTrader: (3)

Raze,
it actually states in the owners manual about the types of fuel you can run your car on (lowest for a sport is 90 ron, lowest for the turbo is 95 ron) and as for optimax its just a better fuel with higher octane that gives engines like ours smoother performance
On your car you may have to do an ecu reset to gain the benefit from SUL as it will take a few tanks for it to start filtering through but for the extra cost its the cheapest and best mod available for your car IMHO

Tony

[Edited by TonyBurns - 6/30/2002 1:06:46 PM]

TonyBurns

iTrader: (3)

As above, for the types of fuel check out your owners manual, section 7-3

Tony

RT

Sure way to know is just to listen for det! If you get it, then 95RON is no good.

Brun

Using SUL has gained me 2 mpg. Even though it costs more to fill up, if i take the better consumption into account, it actually works out roughly £1.70 cheaper per tank.

Deep Singh

Simon,keep some octane booster in the boot for when you c'ant get SUL/Optimax.I've been told on good authority the STIUK will det like mad on 95 RON+welly+hot day.You will also lose power as the ECU retards the ignition to cope with the inferior fuel.

TonyBurns

iTrader: (3)

Deep,
i dont think that you would get det or they wouldnt reccommend the minimum being 95ron fuel for this car, but like you say what it will do is retard the timing to compensate and you will loose power that way
The maps on UK/Euro cars will be very generous in the fuel types, i dont think that Subaru wants lots of engine failures on one of their production models due to det it wouldnt really go down very well with everyone and cost them lots of cash to replace/sort the mapping of the ECU out.
I'd run these types of cars on a minimum of SUL anyway (as i have done with my MY00 turbo ) as it just makes it smoother and i also get over 340miles out of a tank of fuel (unless i push it then it goes down a little )

Tony

ChrisB

"i dont think that you would get det"

Tony, I refer you to Mr Felsteads comments back up the thread

alcazar

iTrader: (2)

Wot really bugs me here is that I'm paying best part of £4.50 per tank of SUL over the price of NUL.
AND that I have to search for the good stuff: there are only 2 places round here that do it (luckily one is real near to my abode), but EVERY LITTLE GARAGE sells it in France, even the crappy little supermarkets in way out of the way places, and, get this,............it's only about 1 or 2 pence per litre dearer.
Just what the f*ck is going on over here?
I wouldn't care, but I only live 20 miles from one of the biggest refinery complexes in the country, but I pay more for my fuel than darn sarf....rant.....rave.....

ChrisB

"but EVERY LITTLE GARAGE sells it in France, "

Agree with that. In Spain for the Rally Cat, we'd be half way up a mountain in the middle of nowhere and the petrol station in a tiny village would have a SUL pump.

chrisp

On a totally standard 208/215bhp UK turbo you run it on 95 RON it maybe not be as smooth or return as much power or mpg but it should be okay. If you run a modified car eg a PPP, unichipped, linked, motec-ed, bleed valved, moddy exhaust, moddy air filter, etc etc or a non UK/Euro WRX or STI then 95 is not really any good and maybe harmful to the engine. Even with the UK cars people want more power but are not prepared to run good fuel, crazy .

It may run okay for thousands of miles until one day its goes bang and you are left with a big bill and your car off the road for weeks.

This isnt scaremongery it happens, you have the knowledge its up to you if you take the risk. Seen quiet a few threads in drivetrain starting "I have blown my engine up". Obviously not all engine failures are down to the fuel but at least running good fuel attempts to remove that issue.

This is why people like scoobynet as you get they experience of a huge amount of owners. Like I say upto you what you do with the info .

TonyBurns

iTrader: (3)

Chris,
Id expect a car that has been mapped for a minimum of 95 ron fuel not to det or else the consequences for Subaru will be rather expensive.... if they have to start replacing engines due to det then id expect a recall of all euro and uk sti's for a new ecu that can handle the fuel.
We are probably more fortunate than other countries in europe with our fuel, look at france for instance, their fuel is lower grade than ours so running euro sti's will have a total failure rate due to higher summer temps and cr@p fuel (ie 95 ron).
Id still expect a JDM STi7 to suffer in summer, even with 98 ron fuel without a remap, but the UK/Euro car should have better retarding to cope with this (thus the reason P1's shouldnt det in summer when running 95ron fuel).

Tony

chrisp

Like I said its your risk, on a totally standard UK car you would be okay. Who in the right mind would run a UK PPP/UK STI/P1/UK 22B on 95 RON. The only reason the the UK cars dont dett as badly is becuase the ECU map retards the ignition further for crap fuel which in turn means you are getting a lot less power. So you spend all that extra money on a performance car and then dont get the best out of it ROFL .

TonyBurns

iTrader: (3)

Like i said earlier, ive always run my MY00 on SUL minimum but there will be places that you wont be able to get hold of SUL/Optimax so U/L will be the only option, the ECU will (or should) be able to cope with this.

Tony

Phil Harrison

Hi Raze.... a "newbie" with 95 posts - ROTFL

Optimax is indeed a Shell-only fuel, slightly higher RON than SUL. If you run Optimax, you will get some fuel economy compensation for the extra cost - maybe enough, maybe not. I've never come across a Shell Station that doesn't have it, and as a matter of practice I fill up when I drop below 1/4 which allows me plenty of leeway.

I'm sure that any mainstream Scooby issed by S-UK ought to run on 95 RON - it'd leave them too wide open not so to set it up. I'm sure that the margins against detting are far less at 95 RON. Consensus seems to be that cars feel subjectively "smoother" with SUL/Optimax: to say there's more "power" would, IMHO, require instrumented demonstration, which would be tedious to set up as you'd have to reset the ECU and run in when you change fuel.

All-in-all it seems to me to be "good practice" to run on higher RON fuel, and there should be economy compensation. Which is why I do it, without worrying too much either way...

Phil
(as "newbie" as you)

Neil Smalley

Going back to the STI-7

You pay 26 or 27.5K for a car and yet skimp on fuel

The STI WILL run on 95 RON, but as the book states IF 98 RON fuel is not available then 95 can be used. That says to me, that normal unleaded should only be used as an emergency 'get you to a SUL pump' measure.

A few people, who's judgement I trust implicitly have said that they heard detting from the STI-7 on 95 RON fuel when the car was being driven hard. That puts me right off 95 RON. If you are going somewhere where SUL will be hard to find then take a bottle or 2 of octance booster and put that in with the 95 RON fuel.

The price difference between 95 and optimax(98.6) is only £2.40 per tank. Seems a small price to pay for peace of mind and better performance and fuel economy.

chrisp

This has been done by checking the amount of advance which can be run before the engine starts to dett, luckily scoobs are fitted with an adaptive ECU and the ECU advances and retards the ignition depending on the knock of the fuel. The more advance you are running the more power available to you. The higher the RON rating the more resitant to knock so the further the ECU can advance the ignition.

X SOOOBY

what gives me the hump is that if i want optimax my nearest shell garage is app. 18 miles away and a direction i dont go very often so that means i have to get esso super at 81.9p a litre so it is not allways just £2.40 a tankfull its the petrol getting there also i live 5 miles from one refinery and 8 miles from another

so come on shell open a petrol station along the a13 in essex you would rake it in there are loads of scoobs and other performance cars here