leegee

Hey guys, was just wondering, do Impreza's, both the WRX and STi, around about a MY04, need super unleaded 97/98RON, or can you put normal unleaded 95RON in them.

This is something i have not thought about.

By the way, i dont own an Impreza just yet, soon though

SamUK

iTrader: (1)

Welcome..!

Do not use 95RON, avoid BP Ultima and ESSO Super Fuel....Stick to Shell Optimax and you will be ok...


Also if you use the search button, you will find allot more info...

fitzscoob

You can use other petrols apart from optimax, I used Super Unleaded from Sainsburys and that was fine. Just avoid 95 Ron and you should be ok.

If the car is a jap import then that is a different kettle of fish.

leegee

OK then guys, thanks for that. It will definitely be a UK car.

What about if i used it just once, by mistake, would that damage the engine...

alloy

Well try and avoid using other fuels. I've been caught short on occasions and stuck in the BP 97ron stuff and the car didn't receive the fuel well, but it is mapped for optimax .

BVM

I only run 95RON now but I have alcy injection for the added octane.
Although after my 3rd tank of bad gas from the Newmarket/Cambridge A14 BP's, I will never run BP again.

SamUK

iTrader: (1)

Yes you can use any fuel even 95ron fuel (if your cash flow is low), but once you invest in a knock monitor you will see just how bad the Sainsbury's fuel is for the car...

IN THE STICKS

If it's a standard UK WRX then you can use 95 ron , but it'll run smoother on 98 and protect the engine better long term

SamUK

iTrader: (1)

So are there any performance gains from using 95 ron fuel to using 98ron fuel in a standard car?

I can't remember there was a showing on Top Gear where they tested different fuels on a Dyno with different cars of which one was a STI, and there was near a 10bhp increaase over 95 and 98 fuel + added torque...though i cant remmber...can anyone clarify?

alloy

the better the fuel the further you can advance the ignition

Studies have shown that by resetting the ecu with higher quality fuel will give performance figures colser to quoted, where as lesser quality fuel with do the reverse. I'll try and find the link, but i think 5th Gear did a test too, that showed the STi achieved an extra 30bhp using optimax in comparison to normal fuel

leegee

Thats all very usefull thanks.

What is a Knock Monitor...

I will be asking a lot of these silly questions until i get my knowledge up, sorry

alloy

knocklink is some flashing lights that indicate det i think. If the car is mapped right and fuel is consistent then its a pointless ugly mod, if you want the piece of mind spend the money for one

SamUK

iTrader: (1)

Ugly, but will save you an engine...car can be mapped correctly but the knock link will pick up dets caused buy other failures also...

When my car was mapped i was detting like mad on BP Ultima, even though this was in the car when it was mapped for...i switched over to Optimax and no issues...

leegee

So if i am planning on leaving the car completely standard, do you think it would be pointless having one.

pete1976

Yes completely pointless on a standard motor IMO.

evertonal

Does anyone have any info on running a FuelCat on my 1993 WRX???Just bought it and Fuelcat reckon you can use 95Ron without a problem
Any ideas

Bug Eyed Peas

He awaits eagerly the arrival of PS Lewis

GREGGYG

iTrader: (2)

The manufacturers handbook states to use Super unleaded fuel.

stevebennett

Agree with GreggyG

97 octane is 97 octane does not matter where it is from.

The ECU in the car is designed to advance or retard the ignition based on the quality of the fuel.

V-power 99 octane, you do not get any performace differences, just changing the ignition timing to suit the fuel.

Tesco 99 octane - approx 220 miles to the tank
Sainsuburys 97 octain - 260 miles to the tank
V-power - 270 miles to the tank
(My experiece to date)

The car is designed to run on any 97 octane and will not cause any damge to the engine. anything said otherwise is just scare mongering

Pakolainen

Bought my 05WRX in august, dealer in the scooby showroom, owned himself a peter solberg edition III, and clearly knew his stuff. anyway he said that the wrx could be run on 95, whereas the STi needed 98.
WRX was bought and have been using 95, cars a real petrol alcoholic, always drinking, but i know that has nothing to do with the ron. but couple of weeks ago whilst filling up i noticed a sticker inside the flap covering the petrol cap.
' this car uses only 98ron petrol'

so subaru dealer car told me wrong. filled up with 98, and as of yet haven't noticed a massive difference, time will tell.

jimmy boo

Read posts on here before which said that the sticker inside the filler cap referred to the Jap RON rating which,apparently,is different from UK.My dealer told me you can use anything in my 03STi as it will adjust itself accordingly.Having said that,I always use V power or BP Ultimate..........The same dealer also said there's lots of rubbish on Scoobynet Hi Keiran

andyfish

It's good to see a big dollop of common sense on SN

I ran Tesco 95 Ron for 12 months from new (MY05 WRX PPP) and moved over to Tesco 99 Ron as soon as it became available - apart from slight improvement in performance and MPG I never noticed anything. If I'm on a long run and can't find Tesco 99 Ron I chuck in a bit of V Power.

andy

wolfie28

What Jimmy boo says is spot on. If you go for a UK standard WRX or STI 95RON is perfectly fine to use however using higher octane fuel is not a problem either as the car automatically adjusts. A higher Octane fuel will give improved performance and MPG. If you go for a STI with PPP 97RON and above should always be used. There is so much contradictng info on Scoobynet with reference to petrol octanes and how folks rate them. My standard UK WRX (owned from new) is over 4 years old with 50k on the clock I've used 95RON, 97RON and V-Power 99RON (Optimax 98RON before this came in) and the car is in perfect engine condition.

Ideally which ever Scooby you go for put the highest octane petrol in you can afford.

Wolfie.

MrRA

Use the best fuel you can get.

Preferably Shell V Power

powerman1

I have put the lot in my MY06 sti and have not noticed any difference at all between any of them....

misty

Knocklinks! Invented by a subaru owner who thought it would be a good wheeze to frighten all scoob owners into believing their cars would blow up without one!!!
What a bunch of sheep.........
Dave