Ahh but that would take a week to read, so if you haven't got a week:-

and the result is that boosters are knock-link foolers, Optimax has aromatics which increase the RON level, and is prone to deteriorating up to 3 points in 3 days.
If you really want to have richer fuel add Toluene or xylene (both aromatics) or get racing fuel.

Thats about 40 pages condensed


edited cos I can't spell

[Edited by adair69 - 11/4/2002 11:26:28 AM]

 

think the general opinion is that Optimax degrades in the tank after a few days.

[Edited by andyVI - 11/4/2002 3:14:29 PM]

 

Eh up a true chemical engineer has spoken LOL (accurate, technical description ), if you dont like it dont use it .

Oh BTW I swapped from Esso SUL and the car is much better thanks .

[Edited by chrisp - 11/6/2002 9:21:46 AM]

 

Filled up yesterday with optimax, gave it some welly and Blackpool illuminations appeared on my knocklink (panic). Car has been running this setup for months now with no probs. Stop car and apply some loving OB no further probs. It would appear that there is some serious degradation that takes place over time with this stuff. I'll now be a nervous wreck every time i go for petrol. Be warned.

Barry

 

I take it you use to put octane booster in with SUL then? you should do the same if you run a JDM import car anyway, no matter which fuel your using as its still below the 100ron rating that JDM cars run at.

Tony

 

Tony i have it mapped for Optimax with the link - i'm very careful with my car and it's fuelling

 

Ah i see
Never had any probs with optimax myself but then again i run a UK turbo (97ron map).
Did you try an ECU reset afterwards??

Tony

 

I run a mix of ESSO SUL with millers or straight Optimax. I have had a few bad tanks of Optimax.
Put Optimax in on Thursday and the whole car is running like a dog put SUL and booster intoday and it is fine. I usually find Optimax O.K. sometimes the car seem to run very well on it. But Optimax seems to be occasionaly very tempremental in my experience.

Steve MY94 WRX.

 

Resetting a possumlink unfortunately has no effect on it recognising fuel types My 93 WRX was also run on SUL + OB until remapped for otherwise(333BHP now).Knocking was defo caused by poor optimax and now NF or the like will be getting more of my business as it's not a risk i'm willing to take.

ps where's best to buy NF (race)

Barry

 

I stopped using after several 000'm on it and a blown engine which may or may not have had anything to do with it, but I also am not taking that chance. SUL now

 

Another, look out Optimax will wreck your engine thread

I think its great!! No pinking, No degrading, But maybe, Just maybe, in 5 minutes time my engine will melt!! ha ha ha

Pete

 

I thought it was pretty good as well. And then I changed my mind.

 

was running Optimax regularly, then bought some ESSO sul - pickup and throttle response seemed to improve, which was surprising.
went back to Optimax, as thought 'must be imagining', then went back to ESSO sul when empty - same noticeable difference. did this over a few weeks to check (all subjective I know, but did do a few 'in gear' times to check, and they are better on ESSO)

not going to bother with Optimax again

(MY 01 WRX)

 

Well, as I have said before, my car ran terribly on Optimax, but improved on SUL plus Octane booster.

Each to their own

It will certainly be interesting to see the long term effects of Optimax on the cars.

 

I've been running Optimax for a few months now Seem to get a bit better range out of a tank and more consistent. Before, i could get around 200 miles on a tank average whereas optimax will take me 250+ No noticable performance increase though

BTW, it's a MY97 UK car. Gone from NUL to Optimax

 

Never had any problems with Optimax, although it's only been available here for about 5months
Just filled up with Sainsburys SUL at beginning of week and got an extra 40miles out of a tank!
Think i'll forget about Shell Plus points and start building up my Nectar balance.

 

P1 hates optimax (stutters), loves SUL.

 

Using a knock link I have come to the conclusion there is some variation in the quality of the Optimax plus N.F. I use but when I experimented with other super fuels the potential for knock was far greater so I think there is no doubt that at present Optimax has the highest RON and is therefore the more logical choice for any Japanese import.

 

Harvey, i agree as optimax allowed extra advance to be added to my ignition map but as you say there is a variation in quality and this is my major concern

 

Just one thing to remember guys (flame suit on)

If you have a degraded Optimax tankful, adding Booster (any of them) does not increase the RON level or protect your engine, it only disguises the knock, that means your engine does not retard when it should!! To lift the points at all you need to add Toluene or suchlike. I'm only saying this so you don't have an engine that goes BANG, not to cause a riot. Its worse for those with mapped ECU's like me (Motec M800) cos the standard STi7 was very adaptable and would retard to as low as 95 after one tankful. Not so when mapped to a fixed points level.
But before anyone tells me adding octane booster lifts it to 100+RON with 1ml per litre, all I can say is each to their own,and this was not to argue against your beliefs just a word of warning.

(flame proof jacket off)

 

What all this about degrading, Shell responded to this (sure I saw an email posted on here) and said yes it woudl but it takes years. As Optimax has only been out a short time its unlikely. What is more likely is SUL degrading as very few people use it and only normally on one pump in a Petrol station that sells it. I would be more worried about the long term quality of SUL.

 

Chrisp

Optimax in independent tests is known to degrade down as far as 97 over the course of a week. I'm not a chemical freak or saying that this is categorically correct, just that the independents have nothing to gain from stating anything but the truth. If you want the best fuel for your car however, I understand that TOTAL SUL has the highest calorific value of any fuel in the UK, and as such is the best. problem being there are less than 70 sites UK wide and decreasing.
I actually use Optimax, and have only had a bad batch once from a small outlet which I think did not have many Optimax customers. I use the same garage most of the time which is very busy on the Opti' pump, and look for busy ones elsewhere if I'm filling up away from home.
I understand that at £1.40/ltr there are a couple of outlets doing 102 RON race fuel, now that'll do nicely thanks

 

Has anyone got that really informative thread from the GT-R forum lying around to post up a link in here?

 

Here's the link anyway for anyone interested :

http://www.gtr.co.uk/forum/upload/sh...octane+booster

Very interesting reading - Mycroft should have the knighthood in the bag !!

 

adair69: Can you provide the independent test information or give me enough leads to find it myself ? Thanks.

 

I think the topic can go on and on and on. THE only way of not causing damage to your engine due to RON of fuels is to buy either a full mappable standalone ecu or a good piggyback system or a TEK2 or 3 upgrade. I have a ma8 who owns an STI V with a link ecu mapped for SUL. He has covered more than 90k miles. Most engines just let go after around the 40k mile mark some even sooner. The WRX's STI's etc were made for the japanese market hence why they were not bought into england at the time. Unfortunatley we do not have the same fuel as our Japanese friends so i say we are treading on thin ice by putting SUL or Optimax as the cars are mapped on the edge anyway.

Cheers

Gez

 

i will be brief

this subject has come up b4 so now i only fill up with what i think i will need for 2 days driving, its a bit of a pain topping up all the time but this keeps (fresh?) fuel going in, i also try to use 'busy' petrol stations as the fuel degrades in the forcourt tanks as well.

am i right that the new (bug) cars ECU resets on the fly? so a bad batch of fuel should not do any damage, just run a bit sluggish?

BTW i top up between empty and 1/4 full. and you should have seen how many trump cars i had

 

I'm not sure about the WRX bug eye, I can only speak for the Sti.
The ECU in the STi I personally think is the best "western and worldwide" (if I can use that expression) ECU the Japanese have produced. My understanding and I'm no expert by any means is that it will adapt and retard right down to 95 RON, it was specifically designed to adapt quickly and by that I mean after a tankful, but it is retarding almost immediately. It is not as the past ones have been, an ECU designed for 100RON and not European or rest of the world fuels. I think that F.H.I have really thought about the global marketplace with this unit and have thought about the larger rather than domestic marketplace.
I personally and its not because I don't think its a very intelligent piece of kit replaced it with the Motec M800, mapped to Optimax. I do however have an ECU which can be mapped to other Rons etc easily. I believe that the Prodrive PPP is a fixed map to SUL, but I'm sure someone will correct me if I'm wrong, which of course means unless your damn clever or working for Prodrive your stuck. To simplify things and to illustrate how clever the unit is, everyone has had air con in their cars for ages and how many times do they make the car run crap, so the clever boys at FHI get the unit to turn it off and put the power to the engine when you want it, personally I think its simple but brilliant!
I know its a long winded post, but I do think the the ECU is well put together and a pat on the back is in order for FHI, even if I dont have it in myself

 

Adair - Toluene is not legal

Plus it don't work as well as NF - FACT.

Plus 1mls per litre does take optimax to 100 RON.

5mls to SUL gives you more ignition than elf race fuel....

 

Optimax = w4nk. Its ****e and wouldnt touch it unless desperate.
end of story!

ESSO (sul) is the best as it has least additives in it. I know this as i had a geeky friend that had to study fuels at uni. Your get more power and mpg on ESSO,its true.