Hi, can anyone tell me what kind of performance difference there is between unleaded and optimax. I have just got my 00 scoob and I have tried both and haven't noticed any!

 

You won't noticed the difference staright away. To speed things up, get the ECU reset.

 

Is it easy to reset the ECU?
Would you say the extra performance was worth the extra money or is it marginal?
Roughly how many tanks full of optimax is required before I notice the difference without resetting the ECU?

Much appreciated

Jake

 

A simple way of resetting the ECU is to just leave the battery unplugged overnight. Simple to see any impact with just one tank in that case.

 

So would you say that there is no point in resetting the ECU as it has been running on optimax for about 2 weeks now?

Cheers

Jake

 

The MY00 ECU will pick up on the Optimax after a couple of tanks or sooner.

 

You may notice improved economy. I picked up 2.5 mpg after changing to he good stuff.

 

There's been many threads about if Optimax is worth it or not. I used Optimax for the first 13months I had the car (owned from new) and over the last month, I have used SUL. I haven't noticed any big differences in performance. I have a MY01 UK300 with ITG panel filter. I would have thought the gains would be more noticable on the Imports designed to run on a higher RON rating. Optimax is supposed to have engine cleaning capabilities and is a bit cheaper than SUL, but it has been mentioned that the performane drops using the Optimax and when changed to SUL and back to Optimax, the performance returns. The Subaru dealer told me when I had a service not to use Optimax, but couldn't give a decent reason as to why. Just go with what your happy with.

 

Optimax is very variable, mainly dependant on the garage. If it's a garage with a low turnover, it's likely the Optimax will have 'degraded' over time (a few weeks) and as such won't be very good - probably similar to SUL. But if you can find a high turnover garage, the change should be quite noticable. Took me, ooo, about a second of accelerating to decide I had found a good station (rather than my local rather iffy one )

 

StevenUK300,
Thats the problem mate, I am not sure which I am most happy with. On the day I bought the car, I had to use NUL as there was no optimax or SUL around and it needed juice fast. To be honest, I thought the car was a bit sharper on NUL than optimax. Haven't ried SUL yet.

Jake

 

Here's the ECU reset i did earlier

http://www.scoobynet.co.uk/bbs/thread.asp?threadid=160769

as for the petrol look here

http://www.scoobynet.co.uk/bbs/thread.asp?threadid=161554

 

To tell you the truth, I'm not sure which one I am most happy with yet. There has been another thread posted on here about Sainsbury's SUL, and people who have been using Optimax say the SUL at Sainsbury's is a lot smoother.
Next Test: Sainsbury's SUL

 

Yes i'm going to try it, not even sure if we do a SUL anymore !!
Even with my discount on petrol i'm going to try Sainsbury's !
I also fitted one of those magnetic thiongs to the fuel line in the engine bay which is meant to line up the petrol molecules and give me extra mpg....have to wait and see......

 

I ran my 99 Turbo on NUL for the first 2 weeks, after the dealer said it was okay to do so.

It always lacked low down torque though and never felt smooth. Switched to Optimax and the difference was amazing after a couple of tanks where it would just accelarate so smoothly and felt like 10% extra power to tell the truth!!

 

i always use Q8 sul.On the pumps it says it is 98 octane,the garage also says it is 98 octane.it does make the car pick-up quicker,smoother.when the car was in for a service not long ago the mechanic said it was one of the smoothest turbos he has worked on (main dealer).it is a totally standard my00 with 23000 miles.i have had my turbo since march this year and had also heard that the petrol can make a lot of difference,at first i thought no way but it does make a big difference to the cars running .the wife even notices it!!
shoppe

 

They might say it is 98 - but then a quite a few pumps still say that If it is SUL then in the UK it will be 97 RON - do a search this has been done to death. Optimax is officially 'enhanced NUL' i.e. it has some clever octane boosting ingredients which is how they can sell it at 98.6 RON (or whatever it's meant to be)

Opitmax does vary - I always use Opitmax and the car has always performed well on it. To be honest I can't really notice any difference between Optimax and SUL. But there is a noticable difference between Optimax and NUL. I'm lucky that the garage I use most of the time is just off the M25 and therefore has a huge petrol turnover, so I guess the Opitmax is always reasonably 'fresh'.

At the Rally in November, we had to use NUL as for some reason Wales appears to be totally devoid on SUL pumps - the car was more sluggish and didn't feel as smooth - back on the motorway, put in Opitmax and the performance comes back (lighlty modded MY01 WRX)

Worth it IMHO.

Chris

 

hi guys , would a '98 uk car adjust to optimax as quick as the later cars. Had to use 95ron as the town ran dry of opti.(thinks........... surely i can't have used it ALL.........)

 

Alright,
Just to let you know the latest. Thats me on my third tank of Optimax and what a difference. The car feels sharper and smoother and my mpg has gone up. This didn't require an ECU reset and its a standard MY00. Thanks for all the advice.

Something else for all you more experienced scooby nuts out there. I was told that a decat system would change my emmissions to the point where it would fail an MOT and that the original system would have to be put back on. Will using Optimax change that as it is a cleaner fuel?

Cheers

Jake

 

Jake,

Leave the centre section cat standard, put on S/S downpipe and back-box ( or alike), run on Optimax. You'll still pass the MOT test although make sure you get the engine nice and hot first.
The bang/buck ratio is huge.

Happy New Year !

Brookie

 

Brookie,
Nice one mate. Cheers. How much bhp does that give you approx.

Happy new year to you too!

Jake