As a long-standing Optimax skeptic (I used it a lot in my Impreza but personally found that Esso or BP SUL seemed to suit the car better), I would also add that you really need to try a few tanks rather than form any views after just the one.

There's a very long thread (gone on for a year) on Scoobynet where the opinion seems to be split into 2 camps:- 1) = Not convinced and Optimax seems very variable; 2) Optimax is fantastic.

After doing 25000m in 12 months on exclusively 98ron+ fuel (SUL and Optimax only), I fall into the first camp and put BP SUL in now and again in the Octavia as I pay for my own fuel now !

BP SUL is only 97 RON as far as I am aware.

I seemed to remember reaading somewhere that Optimax seemed to "go off" if left in the forecourt tank for sometime.

Don't know how true this is though.

Anyone know the best diesel to use as well? All this talk of petrol is making me feel left out :(

My normal diesel comes from Sainsburys (city diesel) only because its cheap, close to my work, and I get Nectar points. I don't know how this low-sulphur diesel works, and whether Esso/BP diesel is any better. I've personally never felt any difference in performance or economy. :drive:

Originally posted by SkodiRS in this post

I seemed to remember reaading somewhere that Optimax seemed to "go off" if left in the forecourt tank for sometime.

Well, fortunately Rochdale seems to full of boy racers, and

for the most part they appear to use Optimax. So hopefully

it should be fairly fresh!

Rob.

What would be really good would be an independent review of fuels, wouldn't it. Hmmmmm...... gets out google fingers - there must be one somewhere....

Nick - Yes SUL=97ron, which felt better for me than the Optimax (98.4ron?).

The 'going off' bit was refuted by shell but all the techy replies and explanations that were produced still didn't convince me - it was just inconsistent and had nothing to do with ambient weather conditions or delusions on the part of the driver (!). With SUL it always seemed to run smoothly and pick up better than UL but not on Optimax. It did hit meltdown on Optimax once though...which was probably totally unconnected.

Devon,

myprevious Octy was a SLX TDi (110bhp) and I found that City

...sorry avout that...finger trouble.

....as I was saying....

Devon,

my previous Octy was a SLX TDi (110bhp) and I found that city diesel always gave me less mpg; the full fat stuff was the best form the mpg aspect.

Cheers.

Adrian.

Its a bit annoying because there is a BP where I live, but Exeter's fuel is about 3p a litre cheaper, due it being a town or better competition or something. Also the BP garage near me is kind of a motorway service station (if you consider the A30 dual carriageway a motorway - I do the speed anyway ) - and they obviously charge more for fuel to prey on the tourists flocking to Cornwall. I'd be going out my way to reach a BP garage in Exeter, which kind of defies the reason behind fuel economy. Still paying over 80p a litre!!

Devon

You have my sympathy and especially re tourist pricing.

In Milton Keynes the prices are always in the top 5% in the country (they say there's no price fixing !)

so its 78.9 for unleaded (diesel 79.9 / 80.9) but at my parents in lancashire u/l was 74.9.

The best one was in late January where fuel was 4ppl cheaper in Fort William and that's in the middle of 'nowhere' !

I did a lot of miles in my A4 diesels and experimented with different diesels. The best for performance was always the one available in France as it wasn't low sulphur !! To be honest I stuck mainly to supermarket/cheapest and about once a month I filled up with BP or Shell which had good cleaning agents in their diesels.

Hope that helps ?!

An optimax user here , unless of course it runs out like it did this weekend , then I'm forced to use 95 octane UL. I would never use supermarket fuel again unless it was a real emergency , i put some Safeway 4 Star (1991 this was!) in my 2.0S Capri and it broke down , i had to have the fuel lines all cleaned as they were full of **** , since that day i have only used Shell , Esso or BP in my car.

Went to fill up yesterday, and Optimax is 79.9, so I thought I'd give it a try...

The car took 46 litres, so that's not quite pure Optimax. No real difference in

responsiveness and speed, but it does seem smoother (but I'm being cynical

and assuming that's just a placebo effect)...

I'll try a few more tanks, see how it goes!

Rob.

Rob

As I'm still a Skoda novice, I'm not sure how quickly the ECU reacts to a change in Ron. On Subarus it used to take time to 'learn' but this improved with each model year until it was 'each time you started it'.

I think you're doing the right thing - try say 3 tank fulls then go back to a branded unleaded (eg BP) and that should allow you to draw a comparison.

Speaking of fuel my capri ran out the night! In need of a fuel sender unit!

Fuel sender unit? Is that part of the car, or a guy with a tank of fuel?

Actually, that's a serious question...

Rob.

It's the thing in the tank which sends the fuel level to the petrol gauge.

Cheers Nick - that was my line of thinking, but in these bureaucratic times it's

hard to tell...

Rob.

Originally posted by Fabpreza in this post

Rob

As I'm still a Skoda novice, I'm not sure how quickly the ECU reacts to a change in Ron. On Subarus it used to take time to 'learn' but this improved with each model year until it was 'each time you started it'.

I think you're doing the right thing - try say 3 tank fulls then go back to a branded unleaded (eg BP) and that should allow you to draw a comparison.

The ECU seems to respond pretty quickly. While I was on holiday in France last year I got a tankful of dodgy unleaded somewhere, and noticed fairly quickly -less response worse mpg. I filled up with 98RON when I got to 3/4 of a tank, and felt the difference straight away! Incidentally, my car responded like that -but my brother's V6 Vectra was coughing and spluttering all over the place!

Phil

Day tripper

I went through a few of those sender units in my Capri days , funnily enough mine always seemed to indicate full all the time , even when it was empty! It took me ages to trust the gauge again. My brooklands tho , it was wierd coz the level of the fuel guage went up a little bit if you put the headlights on , which i hadnt experienced in the other 3 Capris , and it did this for the 2.5 years i had it!

Originally posted by Dmac1969vRS in this post

Day tripper

I went through a few of those sender units in my Capri days , funnily enough mine always seemed to indicate full all the time , even when it was empty! It took me ages to trust the gauge again. My brooklands tho , it was wierd coz the level of the fuel guage went up a little bit if you put the headlights on , which i hadnt experienced in the other 3 Capris , and it did this for the 2.5 years i had it!

have a look at my latest baby

www.brooklands280.com

Studioman

I have a load of pics of my Brookie , keep an eye out for her at shows and such , she is E26 UWE and i still miss her!

So talking of Octane, anyone tried adding Octane booster, just wondered as I have a few bottles of NF sitting in the Garage left over from my Scoob import days. Would it be worth keeping & using for fast days !!!

Stuart

No haven't tried that yet.

Looked for a poll I posted on another group a while back to see if I could cross-post it here, regarding what fuel people used, but couldn't find it. There was a wide cross-section in the responses last time I looked, not at all conclusive.

Currently running on a tankful of Esso SUL. Feels quite perky but a bit harsh - amazing what you can persuade yourself you can hear from your car!!

Which reminds me - was mooching round Tesco yesterday and found a motoring section,

and they had STP injection cleaner, which is a fuel additive that they recommend using

ever 3k miles to clean the injectors.

Anyone any ideas on if it's actually worthwhile?

Rob.