Which do you use? Which do you (or your Scoob)prefer? Why? Is one available where you live and the other not? To what lengths would you go to, to fill up with your fave fuel?

I'd be more than interested to know. Many thanks.

 

I use optimax in mine, seems to run alot better/smoother.

I went away before xmas and my brother had the car for 2 weeks, in this time he used shell super plus. I came home got in the car and was really disapointed, it just felt gutless and on looking at the boost level it was reading 0.5 bar.

I filled it up with optimax and after a day and a few miles it sorted itself out, boost was back up and the car just ran smoother and acelorated (sp?) alot quicker.

I'll use it all the time from now on, defo works better with my car.

It's a import btw so that may be a factor.

 

Well Burr,

My experiences are totally subjective (or is that objective? ) as I have no proof or dyno figures etc.

But I started off running my MY00 on regular unleaded....did so for nigh on 9000 miles....seemed fine to me. Then I thought I would try some super....Definitely an improvement, better perceived pickup, runs better and seem to get better economy (not much, maybe 20-30 miles on a tank). So I have been using Esso or Total Super Unleaded ever since.

Then Optimax came out, and I thought I would give it a whirl, and it is even better than SUL. Again better pickup, e.g in overtaking, the engine just seems more eager and the turbo seems to spool up quicker....again I have no proof - just feels quicker and smoother. Now run on Optimax wherever I can get it, failing that back to Esso Super generally.

And I am not THAT bothered which fuel - Optimax preferred, but I am not going to do a 20 mile round trip to get it! So my local Garage in Yorkshire it's Esso, when I am anywhere else and I see Optimax I will fill up with that!

Jim

 

Esso SUL makes my car go like stink

 

Esso SUL is 79.6p, Optimax is 72.9p, my car is an import and I can't tell the difference between the two - I use Optimax because it is cheaper!!!

Jon

 

Optimax is cheaper but I still use Esso SUL, Optimax makes my car run really rough

 

My old Saab 900 T16s will run 23+ psi peak boost on Optimax without pinking, 20 on SUL, and a pathetic 15 on UL.

On Optimax in cold weather the old girl is good for 150mph, on UL it sruggles to get over 140. Mpg is also better on Optimax.

I hate filling up with anything other than Optimax, which is a problem when I'm at home 'cos it ain't sold in Wales yet.

No, I don't work for Shell.

 

I've asked this on another thread, but does anyone know of any good links to suppliers of octane booster? I'd prefer to use a brand that you guys support.

 

theres something special about esso SUL. my cars an import too with a possumlink (+20PSI) but agree with M, it seems slow and rough on optimax. the higher octane prevents knocking more but it doesnt seem as potent in my car.

 

Hey Kippax

R U someone I know

Sorry for the highjack BuRR

 

if wasn't before i am now. nice to meet u mark u from Mcr then?

 

I run a 1994 MR2 (174bhp model), and since buying it 7 months ago I have used Shell NUL due to the Shell garage being about half a mile away from my house. They dont have Optimax, and the nearest Optimax garage is about 15 miles away.

Anyways, one day I was passing said Optimax garage, needed fuel and decided to put in a full tank of Optimax. After a few miles the car was running worse than ever. Power was down, it was rough around town, and I was V disappointed

Last week I needed fuel and passed an Esso garage. I remembered when I had my 205 GTi I would use nothing but Esso so decided to go back to that rule. What a good decision My car now feels faster, smoother and all together better to drive than ever before. This is on NUL as well. I also remember on Northern Meet 5 I used Esso SUL and it was blinding - very fast.

So its the Tiger for me every time

DW

 

Somewhere round there

Have a suspision I know you.

What you do for a living (not being nosy but I am if you know what I mean)

 

mechanical engineer

 

Well, its OPTIMAX for me no question

MY00 totally standard wagon

NUL = about 18/19 mpg and pinking

Optimax = about 27mpg and as smooth as a babies bottie!!

Esso SUL, yes great - but at 76p?? when Optimax is 72p?? NAH!!!

Pete

 

hi, thought i would throw my tuppence worth in, i have a uk turbo 2000 which was run on normal unleaded, then optimax came to town
i put a tank full in and i cant say i noticed performance changes but the car feels alot smoother and a few rattles seem to have calmed down too. having not used esso i cant compare the two but optimax is fine in mine

 

MY01

I use Optimas as there is a Shell garage 1 mile from my front door.

I was in Scotland and had to use BP SUL and did notice the car feeling sluggish. Back on the Optimax now and much happier car!

Avoiding ESSO as they are going demolish Alaska.

 

Standard MY02 - Used Optimax since I picked it up, Why?

Optimax=72
EssoSUL=78

No problems so far, so sticking to Optimax. Miss WRX what MY do you have.

Boultsy

 

Esso SUL is 97 RON (IIRC) and Optimax is a minimum of 98.4 (confirmed by Shell) and therefore most performance cars should run better on Optimax.
If the scoobies are like the Evos and have a self learning ECU then you will need to put in 2 or 3 tankfuls before you will notice a difference and this will be the reason that some of you have experienced rough running when using only 1 tank. If takes a few tanks for the ECU to get used to the new uprated petrol.

Plus, Optimax is generally cheaper than SUL as well which is a complete bargain.

Just my 2p worth

Andy

 

I had the same proble when I first used Optimax, rought running, jumping & stalling. I put SUL in and it improved, then one of my little Clio friends told me to try again, but to ignore the performance on the first tankful, as this cleans the engine apparently hence all the skipping etc, so I did this and now it's running fine. The only thing I noticed is that on startup I get a cloud of smoke which I didn't have with SUL.
And it's cheaper!!

 

I ahve been running my car on SUL prior to Optimax, been usuing Optimax for the last 3K miles 1.5 months or so.

MY 99 UK Turbo

My impressions - no more than that!
Better fuel econonomy - seems to be 250/260miles per 50L v.s 220/230 miles
smoother running, tickover
better performance - appears to pull harder

Optimax is .73 p per litre v.s .79p for SUL

My other half is runing her Puma 1.7 on it. It seems to be slightly better on eceonomy and performance
Chap @ work running an Astra 1.8SRI - same

There ya go

Paul

 

I'd been using NUL (usually Total) since going to Devon in August 2000 because I was forced to - couldn't feel any difference to the Esso SUL I'd been using up to that point (standard MY99).

However, I did hear that Esso SUL had gone back up to 98RON, and my most convenient garages were both Esso, so I thought I'd try that despite the cost. Seems to be erroneously labelled 97RON and 98RON depending on where you go - sometimes both on the same pump! Anyway, I got better fuel economy (enough to just about make up for the extra cost) and it sounded smoother, but no apparent increase in performance. Been using this for 9 months, then finally came across an Optimax garage and tried it - almost immediately felt smoother and faster, turbo seems to start blowing a few hundred rpm earlier. I should add - I tried it at night at the end of last year for the first time, so the air temp may have been part of the improvement.

Can't compare economy really because my wife drives the Scoob more than me now and she's made it 20% worse (unless that's Optimax's fault - don't think it can be!) However, sod economy, Optimax is cheaper than SUL and definitely better than NUL for me, so I'll use it where possible. **** knows what the missus fills up with though

 

Optimax is more expenise than Esso SUL in derby.

72.9 to 71.9



SUL is better in my opinion, but i got a cossie enjin in my car.

 

It's a bit out of date but quite an interesting piece here I thought http://www.sidc.co.uk/faq.htm under the heading 2.4.1 Type of Fuel to Use. Is it worth going for Optimax if you can only get it once in a blue moon?

 

I used to go out of my way for ESSO SUL as well, but I have now switched to Shell Optimax, the car runs richer and does seem to be better for it, although there are days when I'm not sure. Although I'm using Shell I still have to go out of my way to get it.

My opinion for what it's worth
P

 

EvoRSX, i used about 10 consecutive tanks of Optimax before switching back to Esso SUL and my car went like stink again.

Don't forget a higher octane doesn't always mean a more potent fuel, it just means it knocks later.

Maybe if BR set my car up for Optimax it would be even better.

 

I got my WRX just over 6 weeks ago and when first got it dealer had filled up with cheapie unleaded from local garage....around about 2500rpm noticed pinking...since then have stuck to Optimax and much smoother.............

 

Kippax,
The reason I said it should be better was because if you have a self learning ECU, like the Evo's, then if you're using normal SUL and getting knock then the ECU will detect it and retard the ignition accordingly hence losing power. After detecting knock it remembers and adds a correction factor to the timing map. If you then fill with Optimax and it stops detecting knock (because of the higher RON like you said) then it takes time for the map to return to its origianl value. One way of getting around this is to reset the ECU (disconnect the battery for 15-20 secs on an Evo) and this resets the timing map to its original values.

If you don't have a self learning ECU or you have a programmable ECU thats been setup to run on 95 or 97 RON then you probably won't notice any difference because the timing will have been setup so that no knock is detected when using these fuels.

Hope this clears up what I was saying

Regards

Andy

 

Andy, I agree with all that.

Bob Rawle set the PossumLink ECU up in my car for SUL and of all the fuels i've tried (Optimax included), Esso SUL is very noticably the best. I suspect Esso SUL was in the tank when BR programmed/tuned it.

I agree that if the octane is higher, a standard ECU would 'allow' more boost. In the case of my ECU, it would have to be programmed to do so (doesn't matter how many consecutive tankfulls you use with the Link) and in both cases the effect would be better performance.

My Knock sensor flashes the first LED (normal operation) with SUL and pulls really well and really smoothly. With Optimax the sensor never ever flashes.....but its rough and slow.

I think we are both saying the same thing really. Maybe if BR set my car up to flash the normal operation LED with Optimax, it would be even better than Esso SUL.

Decent thread

Stu.

 

I have been running on Esso SUL (79.9p), but I am now off to the Shell website to find out where to get this Optimax malarky!!

Ta Ed.

P.S. MY00 UK TURBO