StuB

I always attemp to get Optimax when I can. Our local shell garage seems to be the cheapest around at mo.
But I've noticed in a few sainsbury's that their SUL is only a penny/litre more than 95ron. Other local garages sell super for 8-10p/l more!
Is there a real difference between Sains SUL and Optimax?

Dracoro

yup. it's higher octance and has all the cleaning stuff in it etc.

bigsinky

i have found that my heavily modded 95wrx doesnt run as well on the sainsburys stuff for some reason. i stick to BP ultimate as we can't get Shell Optimax in Northern Ireland

cheers

big sinky

Chip

Filled up my Sti in Sainsbugs this morning @79.9p litre.

chip.

chris's scooby

Esso SUL is about 81p per litre round here.

Chris

Viper61

Yep, been using Sainsbury's for a few weeks now. My MY00 (standard apart fro S Sport back box & Forge DV) hates Optimax, huge flat spots but Sainsbury's SUL is fine and at 80.9 a litre it's a couple of quid a tank cheaper!!

Gear Head

iTrader: (2)

Say you fill up once a week. 50L of sul at 79p per litre = 39.50
same with optimax at 86p per litre =43.00.
Over a year thats around 180squid extra. I know it sounds alot, but i'd rather pay for a higher quality fuel than the possibilty of a 2500 pound rebuild. Besides, subaru turbos are 'performance cars' and need to be treated as such.

blue haze

i paid 93.9p per litre today for BP SUL WTF!!!

AR

I use Sainsbury's now and then after a shop as its cheap for SUL and you also get 5p off a litre if you spend a reasonable amount in the store first. Would'nt want to use it all the time but fine once a month.

P.Cole

sainsburys sul lights up my knock link to amber/orange first light optimax only flickers the first green

Gear Head

iTrader: (2)

Theres your answer, Optimax is a higher quality fuel. Less noise on the knock link = better burning fuel. This means less chance of pinking and detonation

Dazza01

You want be saying that when she's in for an engine rebuild
Stop being tight, give her the good stuff Optimax all the way

mightyyid

Sainsbury's and all supermarket fuels are generally from the same refineries around the country BUT the key difference between them and the reason they can sell it cheaper is that many of the additives that have been developed by the fuel companies to help cars etc are not added. In the long run, the opinion seems to be that your car will suffer more than if using the fuel from official petrol stations. Sainsburys' are in the business of supermarkets not fuel, whereas BP et al have one aim... AFAIK this is the reason why, and also accounts for why most cars will not run as well. Performance cars were designed for better fuel, so why buy a Scooby and stick cheap fuel in? If you are worried about fuel economy, buy a Focus! Just my opinion... ;-)

Gear Head

iTrader: (2)

Well put!!!

white knight

"EVO" magazine did an article a couple of years ago about the difference between supermarket fuels and "Optimax". It certainly opened my eyes, and convinced me that Optimax was worth the extra expense.

mightyyid is right in that the Tesco's/Sainsbury type of fuel has nowhere near the extra additives of the premium brands, hence the cheaper price.

Although saying that, my UK MY97 turbo seems to prefer Esso SUL (97RON) more than Optimax (98RON). Wonder why?

StuB

Is Optimax 98 ron though? i had a feeling it was only 95 + the additives.

T-1000

I have used all fuels in my car and I can say that it runs better on Sainsburys than any other. Optimax flat spots and rough at idle, BP ultimate was like sticking normal unleaded in but sainsburys and it flies! No doubt optimax is the better fuel but my car dont like it.

Viper61

So Chris what you're saying is providing I use Optimax it deosn't matter how it runs? Sorry, the way it runs on this 'performance' fuel I'd rather not bother. The advert says 'feel the difference' and I sure can Also, after extensive testing using Optimax in my 'blow any scooby away' racing kart (not to be confused with the arrive & drive concrete mowers!) it destroys pistons!!!! Ran 30 minutes on Optimax and needed a new piston (teflon coating went missing in action!) whereas 9 hours running on Esso SUL and it was still as good as new.

Supermarkets are not in the petrol business, but they do see it as a way of attracting customers. They buy their fuel from any of the market suppliers, but are able to shop around for the best price. Any of the petrol big names can choose to sell at under 80 pence but because it's their main source of income (apart from overprice oil and flowers) they choose to make huge profits out of us!

Like most things in life, what works for you is the one for you.

Gear Head

iTrader: (2)

Believe it or not Viper, the ecu on your subaru learns to adjust to whatever fuel your running it with. It then memorisies this and creates a map to suit. If you constantly run it with sainsburys sul, the map will be for this fuel. The reason it doesnt run well when you bung in optimax is because this is a completly new fuel for the scoob and thus has to create a map accordingly. Alternitivley try resetting the ecu.
Cant explain your kart mis-hap, but im sure shell does not design its fuel to destroy engines as its not good for business apparently. Besides, works ok in ferrari engines. Been quite a while since one of those went bang!!!

Viper61

Chris,

Firstly, I tried Optimax without the above advice. Having 'spoken' to a few more knowlegable owners I did the following:

1) Drained the tank
2) Re-set ECU via battery dis.
3) Ran 3 tanks of Optimax without improvement
4) Took it to a main dealer for service & ECU reset
5) Ran 3 more tanks with no improvement
6) Thought bollox to this and went back to Esso SUL
7) Problem dissapeared almost as soon as I got the Shell out of the system

There are quite a few MY00 owners who have the same problem!

& if you think the fuel we buy at the pumps has anything in common with Ferrari's fuel then you're a marketing mans dream!!!

M444GY

iTrader: (72)

where do ferraris fill up then??

NelsonUK

a Ferrari 348 in bright yellow filled up in the pump next to me tonight when I was topping the Scoob up with some BP Ultimate - so there now you know

mightyyid

Gents
As someone who works in F1, I can tell you that the fuel Shell make to put in Ferarri's in very very similiar to the fuel that you put in your car. Differences are mainly due to the detergents (no need for an F1 car, obviously) and other things such as the smell, which is partly developed to ensure people recognise it as petrol - F1 fuel smells different and harsher. Could you put F1 fuel in your car - yep, it would run but for how long, who knows, as road engines are not designed for it. Could you put Optimax in a Ferrari F1 engine - yep, and it would run etc etc...

Is it marketing - of course. Is it similiar though - yes it is. So be wary of putting everything down to marketing - sometimes you might be doing yourself a dis-service.

As for commenst on the ECU learning, well put. Exactly what will happen. Anyone who tries to convince me that supermarket fuel is the same is kidding themselves. Particularly when you see the breakdown of government tax on fuel, you see that while petrol companies make profits, it is nothing like you think it would be. The only people making a big profit is our very own government!

Gear Head

iTrader: (2)

I just dont see the point of buying a performance car and then filling it up with average fuel. Whats the point? A recent 'Car' magazine artical covered a guy who bought a 2001 f1 schumi ferrari. The Team informed him that it could be run on optimax, with a few additives ofcourse!
Dont the F1 regs state that the fuel has to unleaded and of similar property of pump fuel???
Obviously, if optimax doesnt work in your car, Viper, I totally support and understand the use of a different fuel. However, you do seem to be in the minority. I think this is what some of us are trying to say. What works for thousands of scooby owners, doesnt seem to work for you, which is hard to quantify.

stann01

lol well said viper, think most people on here work for shell or summut!!

mine runs like bag of s**t on optimax, esso sul is fine, better than sainsbury`s (that i stick in sometimes)

mightyyid

Like a number of people have said, the ECU learns the fuel taht is put in, so run it on super market stuff, then fill up with a tabk of Optimax and it will run funny - the timing etc will all be different and will take time to adapt. And while you can reset the ECU it will take time to re-learn, which means more than one fill up of Optimax.

I am quite sure that a lot of cars run differently on different fuels. As we all know, every engine is different and this is why dyno's give very different figures for supposedly identical cars.

Bascially, the higher octane fuel will always give you better performance - it might just take time for you to see it. After all, don;t cars run better when they are clean! Therefore, spending your hard earned on expensive fuel and not 'feeling' a performance gain is also relevant. Horses for courses and all that.

Chrispurvis, you are correct in that the fuel used in F1 has to meet road specifications, although these specs are fairly loose, meaning things like detergents do not go in them. I'd love to stick a can of F1 fuel in mine to see what happens - but it's way too expensive...)

MGJohn

Viper61 and others WROTE:

>>My MY00 (standard apart fro S Sport back box & Forge DV) hates Optimax, <<

Interesting thread

You're not alone with that observation. Maybe recommended by Herr M. Schumacher but not by MGJohn ...

Over a wide period to allow for any variances in deliveries, several tankfuls of OPTIMAX in my MG Montego and Rover Tomcat Turbos shows NO measurable benefit.

Conversely, SAINSBURY's SUL gives better throttle response and about 7-10% MORE mpg! Yes, and I've paid 79.9 or 80.9 pence per litre for it too! Keep it up Sainsbury...

PPPMAT

I always found esso SUL the best with OPtimax being awful. Sainsburys SUL feels roughly the same as esso to be honest.

I'm not paying 10p a litre for nothing - that just mad

Gear Head

iTrader: (2)

I think this is a case of 'each to their own'.
When I first got my sti4, there was quite a large flat spot through the revs. Over the past 7000 miles on nothing but optimax, the flat spot has completely dissappeared. Also, my average mpg has risen from 19 to 23mpg on the same roads, driven the same way. Ive changed the oil twice (every 3k) with mobil 1 15w50. Can only go on experience, like yourself.
The benifits, I must admit, are more likely to be from the fact that ive used the same type of fuel for a while. However, i'd still rather put in a fuel like shell, bp or esso, rather than a supermarket who buys in the cheapest fuel they can.

Gary C

What about the way its kept.

If your local shell has leaky tanks you may get moist fuel ?, if not many people use it you may get old fuel ? maybe your local shell mixes some 95 in with the optimax to boost his profits ?

It might explain some differences