billybiker

No offence Mark but I reckon thats rubbish. Firstly how can it still be 97 Ron if it has octane enhancers and what cleaning do you need???? Until I got the S I've run all my cars on supermarket fuels and never had the slightest snag.

MB

Firstly, your car will be fine on supermarket or any other fuel available in the UK, the ECU can adjust for it so why would you expect a snag? - but you will get better performance from a higher grade fuel. I will find out what spec the base fuel is, but each company do put in their own additives. The guys I know at the terminal wont use supermarket fuel becuase they claim they dont use the same additives as the majors, hence the price.

Secondy, please dont discount that as rubbish. Some of what I wrote in my last post my own personal experience, and im no liar.

My car had knock monitoring devices on it, and it was mapped for Optimax (330 bhp STi V5) If i used anything but Optimax it would det a lot on the knocklink and reduce timing. The guy who mapped it is the best Subaru tuner in the UK (IMO) and showed me what extra he could pull from the car with a good fuel. He also now tells me that he's getting better results with Tesco 99 fuel.

Cleaning agents? Do some research on that one. Carbon deposits form in the engine from unburnt fuel combustion, and if built up, can cause power loss. There have been indipendent tests to show the BP is good at this. There are also anti corrosion additives etc etc...

PS - I work for an oil company but im not being biased here.

I would also add that on the S, im not too fussed what fuel I use as I think it makes minimal difference. I do try and buy super, but not fussed which. On a tuned turbo car it will.

MB

MB

Final point, have a look at the label on the inside of your petrol flap

MB

Blitzspear

Mine is awful on anything but Optimax.

Used BP Ultimate once and thought the car was knackered.

Had to fill up with Texaco super whatever when Optimax dried up over xmas. Didn't go very fast in the snowy condtions but the engine was making an awful sound and there was terrible response when accelerating.

Haven't tried another fuel long enough for any ECU resetting to take place.

Had two engines and both respond the same on anything other than 98RON or higher. Not sure whether my second engine is different in any way as my first was in my MY99.

Sorry for the random input on this thread, just my 2p.

billybiker

Thanks for the reply which is very interesting. I'm no expert, as you obviously are, and I don't mean that in a sarcastic way and this fuel business is new to me. As you say though with an S the supermarket fuel (97 Ron) is just as good as any and as I won't be using my S on a track etc then this seems to be the way forward. I find it a bit annoying when you seem to pay so much for fuel which is probably not a whole lot better. I have seen the label on the car-but where can you get 98 RON from??? Spent ages searching out the local shell garage when I first got the car and because the pumps were full of Optimax posters I ended up filling up with 95 RON by mistake and then spent ages worrying about possible damage to the engine . the BP ones are even worse as they now have an Ultimate Diesel. Thank goodness the nozzles are differant sizes.

pip

some tesco pumps do 99 ron petrol. although some are still 97 ron.

Zeph

I've benn using the Tesco 99 since I got the car last month - seems to run fine to me but then I haven't got a reference point. Has anyone compared the 99RON to Optimax et al?

MB

No probs BB, im def no expert tho! I only know what ive learned from practical experience rather than having any chemical knowledge!

You can get 98RON from Optimax or Tesco 99 stuff.

For outright performance it would seem best to go for Optimax or Tesco. The BP ultimate prides itself on MPG from its cleaning ability, hence its price is close to the 2 mentioned earlier. Dont think its attemting to compete on performace grounds though.

Maybe a tank of it once every couple of months would do the trick!

Putting 95RON in the car wont really hurt it, thats what the knock sensor is there for. It will sort itself out after a few 10's of miles, but might not be as zippy as if it was used on 98.

Some more info on the other thread at the top at the mo too.

MB