I agree 1200 rallycar I have had bad experience with optimax had the car tuned it went well next tank it wouldnt idle then next tank it was pinging seems to vary quite a bit.
For track work I run Avgas there is even good and bad avgas these days the shell lowlead 100 is ok. The Mobil avgas 110-130 is the best Ive found. Mobil Synergy is good too we dont get it up her though :( optimax was $1.15 a litre!!! we get riped off in the country.
Its cheaper for me to Buy 200ltr drums of avgas at a time than to run it on optimax thank god the EPA dont test on the road up here.Big fines if caught
Andrew

MOBIL SYNERGY is best

report of heard on optimax say that it is very inconsistant in octane rating, it bounces up and down from batch to batch

I'm sure BP wouldn't take the risk of declaring their fuels are ethanol-free and then adding it. All BP says though is that their fuels are 'guaranteed'. Caltex and Mobil state that their fuels are ethanol -free in writing. I haven't yet seen this at a BP servo but then I only go to a handful. Anyone seen otherwise?

This is a little more infomation on BP ULtimate i snatched from the BP website


Benny

Ultimate
High Octane Unleaded Fuel
________________________________________________________________________________

Applications

BP Ultimate has been designed to be used in modern high performance cars and motorcycles designed to use unleaded fuels of 98 octane.

It can also be used in cars and motorcycles designed for Premium Unleaded Petrol (96 RON) or Regular Unleaded Petrol (91 RON), including pre-1986 cars that require a high octane fuel.

Pre-1986 cars and motorcycles, and Classic cars and motorcycles can also use BP Ultimate in conjunction with an additive to protect against valve seat recession.

In terms of octane it is equivalent to the British 4 star grade and so is suitable for many classic British sports cars of the 1960s and 1970s.

BP Ultimate is seasonally blended to help cars start easily and to give best fuel economy all year round.

When stored under appropriate conditions the storage life of of this product is 1 year. Note that the volatility of BP Ultimate will change monthly so that there are seasonal variations in composition.

Fuel for use in spark ignition engines. Not for aviation use
________________________________________________________________________________

Main Benefits

- High octane rating (98 Octane)
- High density fuel
- Contains additive that cleans and protects the engine - Low sulphur levels reduce engine wear and potentially reduces maintenance costs
- Lower benzene, sulphur and aromatics emissions
________________________________________________________________________________

Specifications

BP Ultimate meets or exceeds the performance requirements of the following specifications:
AS 1876 of 1990 for Petrol
West Australian Environment Protection (Diesel & Petrol) regulations of 2001 Queensland Environment Protection regulations effective July 2000
South Australian Environment Protection (Fuel Quality) Policy 2001
Fuel Standard (Petrol) Determination 2001
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Storage

All packages should be stored under cover to avoid possible ingress of water and obliteration of drum markings. Products should not be exposed to hot sun or freezing conditions.

Quote:


Theres only a handful of servos in sydney Metro i know of that sell Ultima............It pays to check first before filling up.

As for the ethanol in BP fuel........Would BP risk being caught using high Ethanol content in their fuel???

Benny

Vortex is like BP premium 96 octane.
Only BP that has the label 'Ultima' is 98 octane.

Is there a difference between BP Ultima and BP premium? Older BP servos don't brand it as Ultima and I've stopped using it as an NRMA guy claimed it contained ethanol. Anyone know - I'm back to Vortex.

Optimax is not as good as it use to be.

AZA510 is correct.

Be careful alot of people think Vortex is 98 when it is only 96.

You can still use avgas Marty but alot of people are starting to get good HP out of 98.

good info AZA510........

Shell Optimax is the benchmark as i am told and i am no expert although if we are talking racing i dont think that you can past Drum fuel from specialist fuel suppliers

Cheers
Peddler

I personally use the BP Ultima fuel in the track car......it just loves it. I used to run BP-100 before, when you were able to buy it in 20ltr drums at you local service station.

laws have changed so you cant buy it easily anymore.

Benny