I'm sure this has been discussed many times - the Subaru brochure says use 95 RON petrol minimum, so what's the advantage of using Optimax over normal unleaded - esp given the extra price? I'm picking my MY02 up tomorrow and want to be sure what to put in it!

 

more ignition advance

more boost

more power

more performance

 

I've been running mine on SuperUnleaded since new. Should I consider moving over to Optimax? Is it cheaper? What RON is it?

Thanks

Chris

 

sod all difference to super unleaded (97 ron) when I ran the P1 on it for a few tanks (aside from being bitter 'cos we can't get it in Jockland yet!). I'd run it on super unleaded from day one if I were you.

G

p.s. have fun!

 

Superunleaded is 97 RON and Optimax is 98.6RON therefore you might get more power on Optimax due to as mentioned above as less DET, and it is cheaper at most places..

I run on Optimax, or Superunleaded if I cannot get Optimax, but I am noticing more MPG from Super. Possibly because when on Optimax I plant my foot more!

Try it and see...

Annoyed at Super prices though, LRP is Super with an additive added but Super is more expensive???

Can I run on LRP...?? anyone know if this will damage cats or worse?

JGM

 

I used to run SUL in my MY99 but have recently changed to Optimax as it is 3p a litre cheaper and the performance gains are noticeable ... Optimax is supposed to be 98.6RON, certainly makes the scoobysport backbox roar!!

 

can hear the whistle clearer/louder with optimax

 

Do you have to do something to the ECU to get optimax working well?

 

I have run my MY00 on both SUL and NUL (both for extended periods) and I have not noticed much of a performance difference either way (did notice a huge differene in cost however!).

Does anyone have any dyno plots showing NUL versus SUL so we can substanitate the alleged gains of Optimax etc in the real world.

 

so no-one runs normal 95 RON unleaded then?

 

Not anymore - Defo better with Optimax than NUL. More power and smoother power delivery

 

The new ECU dont new reseting I think. It was a bit of old folk law in any case. Just put enough juice in and the ECU learns the fuel anyway. The ECU reset was good if the system was in a bit of mess and needed to be returned to standard settings.

Its suppose to be safe to run on 95 (on UK spec cars) but it kind of defeats the object of a performance car as you wont be getting full power and the full smile .

 

For those of you interested in proven facts rather than seat of the pants stuff.......

Ralliart tested Optimax and SUL on a RR with 2 different cars. Although no scientific controls were done, it seems more than coincedence that one car got a 4 bhp gain and the other 5bhp.

 

I always use Optimax in my scooby, I can get an extra 20 miles out of a tankful, compared to the Esso sul I was using previously.

I've just switched from nul to Optimax in my 14 year old bmw 325i convertible, and it has made a noticeable difference after just a tankful.
It idles more smoothly and feels tourqier in the mid range.

Cheers

Steve.


[Edited by Steve Terzo - 3/14/2002 6:04:45 PM]

 

I'm running a MY99 Turbo, depending on where i am, i have to use optimax or sul.

But, when i have a full tank of optimax with a ecu reset, the car feels so much better, and the performance and boost is more noticable.

Optimax, octane booster and a ecu reset is even better.

 

I also find the car runs smoother and has more pick up low down the rev range and I get better MPG over NUL... enough to make back the price difference... if I drive like I have Miss Daisy in the back mind.

JGM

 

Millers have tested Optimax at 98.3 and 99.3 with the ob in.My car prefers sul though,which is 98.3 with ob in.Don't know why,just does.

 

i always used bp sul the bp in basildon has 98 octan but when i run it on optimax i notice it pulls better and i also get more miles out of a tank.

 

i always used bp sul the bp in basildon has 98 octan but when i run it on optimax i notice it pulls better and i also get more miles out of a tank and its cheaper go for the optimax if you can.

 

No real reference point here, as I've only done 200 odd miles in the new '02 WRX. But, with the first twenty quid's worth of Optimax splashing about in the tank (and with a 'running in' style right foot), I've got a scarcely believeable 28.2 to the gallon. Bet I'll soon get that down to a more realistic average though!

 

"Shell Optimax is the UK's best performance petrol and is recommended by Ferrari and Michael Schumacher himself, so every time you fill up with this unique unleaded petrol you're already amongst winners. Between 14 March and 15 May every time you fill up with over 20 litres of Shell Optimax you'll also be rewarded with an Optimax gamecard and the chance to power off with one of the above prizes.…"

 

What? Power off with Mick Schuy? No thanks I'd rather have the Ferrari and some of those pit-lane girls

Neil
Sussex

 

Optimax is Rocket Fuel! My Sti absolutely loves it (so much so that it drinks it at a truly alarming rate )

 

So where are we at here ?

(Most of the time I fill with Esso Super)

1) Optimax seems the best bet but I'm still getting conflicting stories about whether an ECU reset is necessary if you've run it on 95 or 97.

2) Is Optimax cheaper than normal SUL ?

3) Octane boosters - Trying to find one that's going to give me performance without damaging the enging (lead content etc)

4) Is warranty affected in any way by using OBs ?

Views ?????

 

Watch out!

Italian magazines have tested the Italian version (V-Power 99 ron) and found that dryies internals very much, although performance is increased. The suggestion is to do some tanks with one and then some others with 97 ron.

C.

 

Jack

Have not seen this at the Shell stations nr Bristol......


I run Optimax plus 1 bottle of Millers minimum, should be around 100 Ron...., allows plenty of advance down South

Up in Yorkshire this stuff is pants - I believe they put Ordinary Unleaded in the Optimax tank - as I get excessive knocking and have to back off - a particular culprit is the Shell Garage on the M1 Northbound, just south Of Sheffield - the knocklink lights up like a XMAS tree - proving that I have a dodgy batch of fuel, only problem is its always dodgy from this garage - so I now keep away. Never had a problem down south - had numerous 'bad' batches up North!

 

hi ya, also from a dark place near a long pier. i used optimax and noticed the power difference but not on the mpg front. Ob's EMMMMMM i would stay away from them, there so many differing opinions.

scottscooby.

 

Ta,

Not worried about MPG (otherwise I wouldn't have a scoobie). I'm sceptical about OBs particularly as I'm under warranty with a standard WRX. Too lazy up to now to hit the Shell at Rayleigh Weir when the Esso is just down the road.

Think I'll stop being lazy and use it full time.

What about ECU ? Any real effect given that I've no performance mods ? (But a very fine skirted, spoilered, moretted, grilled quickshifted example it is)

 

Otpimax in only Gaurenteed 98 RON - From Shell. The MON rating is the same as SUL there fore no more advance can be run at the top end, which basically means the same BHP no matter what fuel is used. However at the bottem end the torque curve could be increased as its approx 1RON more than SUL.
So your car might feel better on acceleration than the pull higher up the REV range where the MON charactistics of the fuel take effect.

You should not really use NUL in any turbo charged car, especially if driven hard, this can create DET at the top end of the REV range.

You can however use an Octane Booster to increase this, Millers will take NUL just about to SUL level and increase SUL to about 98.7 and full optimax 98.6 to about 99.8.

Pro Boost gives a 2 RON increase on full strenght.

NF gives more for less liquid used - works out the cheapest one of all.


Regards
Nic

[Edited by NicH - 3/15/2002 1:07:28 PM]

 

The promotion only started yesterday, I've had two - non winning - cards already