Tim Caddick

A friend of mine mentioned an article in the Telegraph yesterday, which suggested that if an Impreza Turbo driver filled-up with Shell's new Optimax fuel, he would gain as much as 40 bhp! Now I did get this titbit second-hand, so I am doubtful, so has anyone out there tried this stuff? Do you get a noticeable increase in power, or is it just a crock of old guff?

wah

I Have been using this now for some months and I can't say I have noticed a 40 bhp increase lol

I found it runs a lot smoother though

NBW

LOL.... my standard car now kicks out 260bhp, does 40mpg, never needs servicing or tyres and my insurers have re-classified it has group 6... all thanks to Optimax....

40bhp? I think not! 4bhp? May be, but it definitely seems to make the engine run nice and smooth and pull cleanly.

Tim
PS Broquet anyone?

steve McCulloch

What utter pants

Oh.. to throw a spanner in the works, I have noticed a huge problem with Northern Shell Optimax - its like unleaded - my Knocklink lights up like a christmas tree when I fill up in Derby/Lancs or Yorkshire! -so be very careful... I am not alone in noticing this...

Down in Bristol/Swindon I have no Knock at all -explain that one Shell!! - I'm tempted to get it tested and see what Shell have to say!

JohnD

iTrader: (5)

Steve
What lights do you actually see? I have the two green flicker at me if I give it some serious throttle. The Link was mapped on Optimax.
JohnD

Trout...

How many lights you see on your knock link will depend on how well it was set up - it is fully adjustable and so the actual number of lights will vary. If set up perfectly you might see one or two lights max at full chat.

Trout

nigelward

Didn't believe that the Telegraph could make such a **** up but here it is (Honest Ron is the title to look for):

What a load of rubbish

The comparison is between 95RON and Optimax. The minimum is 10bhp the max is 40bhp, so why do people get PPP and decat when the local Shell garage will give them similar gains .

The only time I could think of a 40bhp increase is if an owner of an STI import had attempted to run it on 95RON (if the engine lasted) and then decided to use Optimax which is closer to the fuel it was designed to run on.

SimonH

I mailed Honest John this morning:

"I was delighted to read last week that Shell Optimax can up my Impreza's performance by up to 40bhp over UL RON95 fuel. I believe, on reflection however, that this may be somewhat optimistic; Prodrive's £2000 Impreza Performance Pack (ECU, exhaust and intercooler pipework) only liberate an extra 32bhp (ish) on the standard car. If £40 tank of fuel can beat this then I suspect Prodrive's R&D men may need to get back to the drawing board.
I'd suggest Optimax only liberates a couple of extra horses although it does provide for much smoother running plus some increase (subjective) in response."

I received the following swift reply just now:

"The Impreza turbo is designed in Japan where 100Ron fuel is freely available and all performance cars are designed for optimum performance on 100Ron fuel. They have to be retarded and otherwise mucked about with to run on European 98Ron Super or British 97Ron Super and are seriously down on power running on British 95Ron Premium unleaded. The Mazda RX7 twin turbo lost 40bhp in Euro spec. This is also the case with Italian and German high performance cars and turbocharged Volvos, the performance figures and fuel consumption of which is measured on German 98Ron petrol, which for that last little bit extra, inevitably means 98.5Ron Shell Optimax. Most Brit drivers of cars which should develop more than 200bhp are used to driving 20 - 30bhp down because they are mean enough to save a few pence by filling their high performance cars with 95Ron petrol. The only modern, reasonably high performace car actually designed to develop its 200bhp on 95Ron is the Honda Civic Type R which, of course, is built in Britain.

HJ"

I believe I'm right in saying that the above is true for imported scoobs (WRX and STi) but that the ECUs in UK cars are mapped to run RON95/97 and that higher octane fuels don't really do much. Is it also true to say that the internals on a standard basic jap car (i.e a 260bhp WRX) are slightly uprated to cope with the higher octane fuels?

I'm penning a reply - any thoughts/additions/corrections?

chrisp

I would love to see the bench dyno graphs, (not a rolling road one ) to support these statements.

Puff The Magic Wagon!

iTrader: (2)

Like the technical term "mucked about with"

Active

Interesting comments Steve..in answer to your question...I wish you would, I`m sure a lot of people would be interested in the results.....
Good one Simon..When you say imported car (Jap spec?).. I`m importing one from Belgium (arrives 14th March)so I`m interested in all your comments as I was intending to run it from the start on Optimax so that the ecu "learns" from day one. So what would my imported GB spec be mapped at...would you know?.
Regards to all
Bob

chiark

Steve, put me down as another "optimax=more det" too. (Must think it's OK for us northern monkeys...)

chiark

So, basically he's saying "run a Japanese import on Optimax and you'll get 40bhp more than running it on NUL?"

Someone must have a dyno of this...

nigelward

Or running a UK Scoob on 95RON will only give you 170-200bhp.

If Prodrive quote 225bhp for a PPP running on 95RON, surely the 215bhp quoted by Subaru (MY01) is also for 95RON.

The Subaru web site doesn't explicitly say which petrol was used for the performance just 95RON min.


[Edited by nigelward - 2/17/2002 4:18:43 PM]

nigelward

Another idea, maybe Honest John works for Shell...

Active

Chiark...us northern monkeys!...even us simple folk totally believe a gain of 40bhp is possible by just using Optimax....we do we do! cough. But as I said to Steve I`d love to see a RR test..very interesting methinks.
Now come on you educated chappies, I intend to fit a Defi boost gauge and a knock link? I`ve seen a Luminition air fuel ratio meter that looks attractive at £95.55 from Demon Tweeks is this the same as a knock link? sorry for appearing a bit of a muppet but I thought the two were the same thing, or am I wrong?
Regards all
Bob

Cosie Convert

I have tried Optimax up in Scotland and see no difference on my Knocklink or Performance meter from using BP SUL. I certainly can't run any more boost pressure without Det.
(Jap Import WRX running 18 PSI)

I'd like to compare some Southern Optimax though ???

cc

pslewis

I am in the South and had to get some fuel quickly on Friday so put NUL in (after months of ONLY running OPTIMAX) the engine ran like a bag of nails!!!!!!!!!!!

I am filling up with Optimax tomorrow, cant wait!!

I would say the engine is MUCH smoother, pulls better - as for 40 BHP increase???????????? NAH - its cobblers ...... would HIGHLY recommend it though! ........... if only for the improved MPG 26 instead of 18/20!! pays for itself!

Pete

Anthony King

I recently asked if there was any benefit in running a PPP'd Scooby on Optimax + octane booster (i.e. can the Prodrive re-programmed ECU recognise the higher octane level) or am I simply wasting money?

The answer I got back from Prodrive was that Optimax gave a benefit but that the Octane booster would produce only a tiny benefit that is not worth the cost or hassle. Essentially UK cars are not set up to run Octane levels much higher than 98-99 unlike the Japanese market cars.

Stuart J

I agree with Pete, I have been running my STI on Optimax since it came out but could not find any in Cornwall so had a couple of tanks of SUL, car ran rough as hell, even to the extent of developing tremendous hesitation after a quick thrash. A couple of tanks of Optimax later and its back to its sweet running self