Yorkie

Does the use of this fuel make any worthwhile improvements to performance. I am talking about accelerative response. Is it worth the extra ? Any ECU resets required ? Does the MY01/2 WRX run better on it ?

PJS774T

I've never put regular unleaded in mine. If you went for the Prodrive pack on your MY01 WRX you get considerable performance improvements and slightly better MPG from SUL.
Apparently, the way your engine management works, every time you start your engine, it logs your knocking point and adjusts accordingly thus reducing performance. Reverting to SUL wont instantly rectify this drop in performance as it works on an average and would theoretically take an infinite ignitions to return the initial performance (unless you get Subaru to reset it for you)
I've only read this and cant comment from experience.
Draw your own conclusions...it's only 6p per litre difference
Paul

MisterToad

This was one of the questions I asked the garage and they said that as UK 'unleaded' is 95 RON then the car treats this as 'super' anyway. If you believe anything they say....

father_jack

Jeez - i hope you don't let them service your car

PJS774T

Subaru say...

"The WR Sport Performance Pack increases power to 230 PS using 95 RON unleaded or to 245 PS using 97 RON unleaded."

So i guess it'd make a bit of a difference to a standard WRX also.

Paul

chrisp

Dealer told me to always run on SUL back in 1998 in my UK turbo so I did. I have a Jap import now and if you dont run on SUL then you will have a very big bill . If you want the performance from your performance car then put in SUL.

[Edited by chrisp - 2/24/2002 8:54:24 PM]

Yorkie

But isn't this fuel being phased out ? There seems to be fewer and fewer pumps available at the petrol stations I visit.

PJS774T

Yorkie

I don't think it's being phased out or Shell wouldn't have invested in the development of Optimax.
However, as more PFSs are franchised, the 1st thing the franchisee seems to do it stop selling SUL as the demand simply isn't there.

Paul

hunswon

No Super Unleaded, what are we all going to do?

ChrisB

From yesterday's Daily Telegraph Motoring supplement:

--------

Sales of SUL petrol in Britain are way below other European counties where there isn’t the same duty and price differential, but they do seem to be levelling off at 4 to 5% of total petrol sales.

”It’s useful for companies to have a prestige product to draw customers into their stations” says Ray Holloway (Director of the Petrol Retailers Association), “so it’s unlikely Britain will ever go to a single petrol grade”

BP confirms that sales are steady and it will continue to offer it’s SuperPlus fuel, whilst Shell is actively exploiting the market. It’s SUL is being replaced by Optimax, a high octane (currently 98.5RON compared to 97RON for SUL) petrol that “enables advanced modern design engines to work efficiently, thereby delivering more power”

Favourable comments are flooding in and it seems the beneficiaries are not just the TVRs and BMW that need SUL: Honest John reports almost 10MPH higher top speed in his std. 2.0 litre Mondeo running on Optimax.

{Some Shell PR blurb cut out here}

Impressive claims, to which other petrol companies might respond with similar products. Best of all, Shell is pegging the price at 4p to 5p more than UL, putting Optimax on a par with LRP.

SUL is still widely priced higher than LRP, an industry scam that fails to reflect the fact that LRP is SUL with an extra additive introduced at the distribution stations. Interestingly, Optimax is being shipped all over the country from Cheshire, which in itself should add to the cost.

--------

I've been running on Optimax for a few weeks now but couldn't really tell the difference between UL, SUL and Optimax. I had my 45k service done on Thursday and I think the dealer has done an ECU reset. I booted it coming off a roundabout coming home Friday and it felt totally brutal compared to pre-service performance. Last time I had it serviced I was still using UL, so I so suspect it's noticed the Optimax properly.

I'm going to ring tomorrow to check if they did do the reset.

scooby_si

i doubt yer dealer has just reset yer ecu as part of a service i have yet 2 find a dealer who has the select monitor & doesn't fob me off when i ask for an ecu reset Oh well that's work in progress but i cant believe sum of u people it is only optimax 4 me i mean i have a high performance car in the scoob i aint fillin it with shyte i mean petrol bills never guna b cheap but if u want cheap fuel then get an oil burner god damn it lol
Si

Scooby_Maxus

I've only run my Scooby with Optimax since new (MY01), so cannot comment other than fuel consumption varies greatly (Worst 220 miles per tank, best 310). I was under the impression that the new engine mgt system fitted to the MY01 resets itself every time is driven (?). That said, my other car run my sweeter on Optimax (normally aspirated twin cam).

You pays ya money and takes ya choice.

bug-eyed wonder

Something doesn't add up here 300 miles per tank
I haven't got over 210 no matter how i drive mine, fuggin thing must be broke

Madman

Ran my MY01 on unleaded at first then changed to optimax, you can tell the difference.

BEW - take them lead boots off mate

Goldfinger

Always had SUL (from Sainsburys) in my motor and has run well but recently tried Optimax again and I must admit after a few tankfulls it seems to pick and pull harder ... and the SS BB seems to roar a little more which is always nice

SUL is still about 4p a litre more expensive than Optimax so I'm sticking with the latter as its cheaper and seems to be better. I also seem to be getting more mpg - done 315 miles on this tank and the red light still hasn't come on. Most I've done on one tank is 380 miles on the autobahn on the way to Croatia last summer on 98RON SUL from Germany going a constant 85-90 mph but the worst I've done is 160 miles

Cheers
Phil

PJS774T

380miles ?!!
Isn't it a turbo ??
Paul

Davej_Smith

I've run on Super and Ordinary unleaded (MY00) and there is only a slight difference right at the top of the rev range (not worth the extra cost IMHO), what does make a big difference is the ambient outside temperature, if its below 6 degress or so there is a big difference in performance, since most people fill up in the morning this could be confusing the super/ordinary debate.

However the difference between the Jap STi 7 (280ps) and the UK STi 7 (265ps) is down to the mapping to use our ordinary unleaded (95ron), so there must be a small benefit.

Chris@Excal

Just changed to using Optimax after 7 months on SUL. Found with SUL that it had a real dead spot at 6000RPM. Optimax has stopped that and it will pull all the way to Rev limiter. Well worth the extra, haven't noticed any difference in the fuel consumption though, how on earth did you get 380 miles!!

ChrisB

Scooby_Si - Just rung Holdcrofts and they did indeed do an "ECU Code Reset".

Optimax - yeah baby!

I've had about 320 miles out of a tank UL twice before. Once was coming back from Scotland and included a couple of cross country blasts but mostly large chunks of M-way cruising.

scooby_si

Ew wheres this holds place can i make it on a full tank lol

CallumW

The reason you SHOULD use super is that the Japanese fuel is 100ron which is what the engines are designed for.

In effect you are running them slightly lean of power, even on 97ron SUL.

It was something I read HERE


Callum

ChrisB

Not a million miles Si - Holdcrofts are the Scooby dealer for Staffordshire and are in Newcastle-under-Lyme.

Goldfinger

Paul - yeah, mine is a 99MY Turbo 4dr with Scoobysport backbox and ITG panel filter. I couldn't believe it either, when the sun was out and the speed was constant it just seemed to keep going and going - I regularly got 350 miles on a tank at that speed on those lovely German roads

Cheers
Phil

PS With a mixture of driving I normally get c. 240-260 miles from a tank without the red light coming on

kurubi

I just dont get it, Is anybody at all using Proboost or millers or any additives in there SUL or Optimax?? I was told that my car ( 99 STI 5) would blow the bonnet off if i run it without it.Also i can only ever get 280 miles tops out a tank EVEN driving like Miss Daisy??
Your thoughts.

R.