I have just joined the Subaru lif style and love it..

Quick question, do I have to use 98 ron fuel in my 2004 WRX ???

Thanks

 

You don't have to mate but you will get more out of it if you do. They just run better on it.

An expert will be along in a minute to tell you why.

 

Ha Ha like it mate! Anyway you should use 98 if you can ( i actually use 100) because thats what the engine likes and is supposed to use. Basicly if you use a lower ron the engine will start to either 'pink' as early combustion starts forcing the piston down while still on it exhaust stroke comming up or in some case's (especially if u use too high ron on old crap cars, not a prob on the scoob) the engine will internally have a melt down. not good.! Willsy

 

You can use 95ron if it's a uk car, but most of us find it's worth the extra paying for optimax.

Dave

 

Its a UK car - its mapped so it is able to run on 95 RON without pinking/detonation or damage. So if the car is 100% standard and is a UK model do not beleive the scare stories!! - or just read the owners manual instead!

It wouldn't meet Euro (2 3 or 4) emissions standards if it couldn't run on 95


Btw - it's when the fuel ignites on the compession stroke before top dead centre (BTDC) - not the exhaust stroke (that would be backfiring caused by missfiring from too lean/ too rich/ bad ignition system and excessive carbon). Also high RON does not cause problem in old cars. Although they would benefit from a few degrees more ignition advance- not sure where you heard that one from!

 

The owners manual will say to use 98ron if you can get it, it also says it's safe to use 95 if you have to.

Dave

 

PMSL...i have seen some bollox posted on scoobynet but this has to be in the top 10!!!!!!!!

 

Subtle Jonny

 

Alright hands up got the bloody stroke messed up! however the higher the ron the hotter your engine runs, as they combust at a higher temp. So personally i wouldnt use hi ron on old cars(and i mean all types not just subarus) It also says on the fuel flap to use 98!!! 95 is crap and u will not get the full potential fromyour car. Willsy

 

Not entirely true, but on the right track

 

thanks people

 

Not all Subarus are the same!

Because yours say 98 on the flap - it doesn't mean everybody elses says 98, a good many UK cars will say 95.

Also most filler flaps say Gasoline - in the UK its called petroleum we use RON, many other countries use other octane rating systems. So make a note that it's the research octane number (RON) and not the Pump octane (PON) or Motor Octane (MON).

 

Ron has the highest value for fuel quality, so if it says 98 if it's mon(doubtful) or pon(if you're in the us) it's higher octane than 98Ron, so why worry.

That's why crap US 92 octane fuel (PON) isn't really that crap at all, it's 95RON.