Matthewp93

Hello guys just this week bought my first subaru.
It's a 2006 Subaru Impreza Sti UK Type.
Currently on 73,000 miles not much details on what the car is exactly running at but the mod's I know of are
-Cat back Nur Spec Blitz exhaust system
-There was a decat on but was taken of to pass mot and the guy at subaru informed me that he's put the sports cat on and thinks it's been mapped to that sports cat it feels very quick not knowing exactly what bhp a few guestimate's are around 330bhp.
Anyway that's the details on the car, I live in a cap town with only esso 95 and bp ultimate 97 the nearest jump in octane is 40 miles away where these is shell and tesco 99. I've read a lot on these forums a lot of people say that it can be ran on any fuel in UK hense 'type uk' others basically telling me that a full engine rebuild is on the cards if any less than 98 octane goes in. Also read on octane boosters etc can anyone clarify to me the best thing I can do and any advice please. Cheers matt

forgedmarco

iTrader: (10)

IMHO you should get the car mapped for the fuel in your area and you can check if everything is running properly whilst being mapped. If you run lower Ron than it's mapped for then Engine rebuild will be in your future. Cheers Marc

GH80

I would say 97 is fine for a Sti. I wouldn't put less than 97 octane in though. I think the main thing is not to go silly and drive with little boost for a tank or two after changing octane, especially going down from 99 to 97. As far as I am aware there is some learning possible on the ecu, but not enough to compensate for de-cats, engine mods etc.

For all the naysayers - all cars in Northern Ireland have been run with a maximum of 97 octane as there is nothing else available. Failure rate does not seem to be different here to anywhere else, and lots of you are buying your widetracks imported from N.I. now as they are much cheaper here!

I had mine (05 Sti) given a full ecu, afr & det check by a reputable tuner on 97 and there was no issues. I think if you were running on 99 then put a tank of 95 in and went mad with the boost it may cause problems.

Not 100% sure on the above but that is my take on it, please correct me if anyone knows otherwise.

Edit - Didn't read the part about being mapped. It should be ran on whatever it was mapped with. 97 might be fine for a standard ecu but the safety margin on the map will be reduced.

piehole1983

iTrader: (7)

Such a pain in the *** not being able to get 99 here any more......

Jay m A

iTrader: (2)

As people have said if you are unsure about the cars mapping history then invest in a remap, and choose your mapper wisely. I'm sure you will research fully, but to help you along the 3 I would consider are Andy Forrest, Simon Roe (Jolly Green Monster) or Paul Blamire (Zen). Out of those 3 the one you choose would be more to do with availability and location rather than ability since all are excellent at what they do. Other mappers are available!