Jason uk

This might seem like a question that comes from complete ******** (it is!).
Would filling my standard UK300 with SUL do any harm or is it better for it?
It seems to run better on SUL but am I doing it any harm.

Juk

Neil Smalley

No it won't harm it at all. In fact it will do just the opposite. IF you can afford the difference in price use Super all the time. Normal 95 RON will do as a minimum, but you will see improved response and better Mpg from super.

see

Jason uk

CHEERS

BarryK

I noticed on Subaru UK's site that since the MY01 became the current model, the tech stuff on fuel says 95 RON (minimum). It used to just say 95 RON, cos it was a big deal to get such wizard performance from 95 RON fuel and I guess they thought it would appeal to the brainless buying public.

ie. Us.

Ask anyone in your office/pub about super unleaded and they'll say why waste your money, it's no different.

Arrgghh.

I even had an old boy in a petrol station say "you really need that, they all run on normal nowadays".

OK then.

Oh and Jason, don't mix tanks, it always takes the lowest common denominator and needs 2/3 tanks of SUL to readjust.

[This message has been edited by BarryK (edited 16 August 2001).]

Pete_UK99

I asked my Subaru dealer about this and he said you wouldn't really notice the difference between 95 and 98. But from what I've heard on this forum that simply isn't true. Also I think you have to have the car tuned to run right on 98. Well thats what my Subaru dealer said.

Neil Smalley

Pete.

The car will 'tune' its self to run on 97 RON. You may need to wait a few tankfulls before it does. OR you can 'reset' the ECU to clear the settings and do it all in a single tank.

One trick that worked with my MY00 with PPP was to stick in 97RON+octane booster=99RON. Reset the ECU then go back to 97 RON again. As long as I did'nt thrash it on the redline the ECU would remember the higher boost settings and i'd get more performance out of the car. Over time it did wear off though

Look at

ScoobySnack

Had both 95 and 97 in my tank.....

Now use 97, for the last 5 months as it does make a difference......

J

BarryK

Should have said this topic has been discussed many times before and the technical bottom line is:-

Pre MY00 (and some MY99) ECUs will teake forever to adjust to a change in fuel. Retardation is instant.

Post and including MY00, the ECU has a "floating point" within parameters it can adjust to "better" fuel.

A UK spec car will not run (and will be damaged) on less than 95 ron, and is unlikely to be affected much above 98 RON, since those were the levels available in the UK at the time. The parameters cannot be open ended for obvious reasons, see any 'O' level physics text book.

Non UK spec cars (ie Jap model direct imports) it seems generally want a higher RON, so a min of 97 plus booster is favourite, whilst in the land of the rising sun they use 100 RON.

Dealers always say "95 RON" because they don't want abuse from people who put higher RON fuel in and can't tell the difference. And maybe it sells the car to some people that it isn't at all "special".

Blues

Just switched to SUL after about 5 months on unleaded.

Noticed a difference after about 3 tankfuls. Idle seemed sweeter ... but I may have been looking too hard for improvments !!!

Try