Not sure if this been posted before but they do 99octane fuel now, thats better than optimax aint it



Filled my cossie up with it just before I broke it DOH!

 

1. Optimax
2. BP ultimate
3. Tesco 99 RON

Test was done if PF mag if i remember[/list]

 

yep above post is correct even tho it has a higher ron rating than optimax its nowhere near as good !

matt

 

oh bet stay with the tried and tested optimax then, well when ive fixed her

 

its not all about the RON levels - its the MON levels that mean the business

 

if i remember correctly the difference between tesco fuel and optimax fuel was at least 20hp

mattv

 

mon levels? what they?

i thought it was just down to octane rating? meaning how well/efficiently it burned?

 

Seems a bit much

 

There is more to fuel than OCTANE!!


One day I'll finish writing the article I have !

Alex

 

Take a look at the fifth gear tests if they are any help
http://fifthgear.five.tv/jsp/5gmain....143&pageid=275

On ordinary unleaded the Impreza put out 235 bhp.
On BP Ultimate, it managed 248 bhp.
And on Shell Optimax, it offered 249 bhp.

Ordinary unleaded gave the lowest torque with 232 ft lbs.
BP Ultimate produced a much healthier 248 ft lbs, and
Shell Optimax was even better, producing 258 ft lbs.

 

I wonder how much Shell paid for the advertising?

 

Octane rating is a measure of reistance to detonation/pre-ignition

Unless you can advance the ignition timing on your car or have an 'active' knock sensor than can advance the timing you wont really see much gains at all

pmsl at people quoting specific horsepower gains, they only relate to the specific car tested in those specific conditions.

 

The magazine that did the fuel test, DID alter ignition to suit the fuels - Optimax came out on top on the YB.

 

Motor octane rating, usually gives a reading 8-10 lower than that of RON. More accurate because it is tested in a more realistic arena. Ie. the engine that they use to test it is subjected to different ignition timing, compressions and the fuel is also heated before use IIRC. This in turn gives a more realistic reading of what your fuel will be like once hot and under warm engine conditions

 

Isnt it true though that all the big petrol companies tankers just fill up wherever is closest so its not the exact same fuel in the pumps all the time?

 

are these gains for turbocharged engines only or will you see improvement if use optimax in a normally aspirated engine too

 

I only ever use optimax in mine

 

ignition timing

 

fill up the same base fuel and put in their own blend of additives from what i've been told

 

Would like to know that also

 

ok guys, as a tunner will tell you if your car is set up to run on unleaded then thats what you should put in, if your cars been chipped and set up to run on super unleaded then thats what you should put in ..common sense realy mine was set up for super and says it on the paper work from m.s.d at the bottom of the receipt, thers no point in putting optimax or any other super if your cars set up for unleaded

andy

 

Surely you can't apply that to all cars?

 

its all to do with ignition timing! whats the point in using super if your timing is set up for unleaded

andy

 

Maybe some of us have engine management systems a bit more advanced than the MFI unit on your series 2 turbo.

Sorry chap i know what your saying but it doesnt apply to ALL cars

 

Only two things you can do on an N/A car to take advantage of higher det resistance, raise compression ( bit difficult without rebuilding it..lol ) or have the ignition timing altered either via chipping or if your car has an active knock sensor and can advance ignition itself....it's been said about three times now, how hard is it to understand?

 

If you noticed I asked the question about 30 seconds after you had answered soemone else about it... hence did not see yours

 

Buy your food from Tesco and your fuel from Shell IMHO

 

Tesco dont make the fuel though

http://www.greenergy.com/products/99_octane.html

 

I didn't say they did, did I James ?

Which is why I said buy only your food from there

 

What I mean is that going by the specs, Optimax and Tesco are literally the same MON rating

 

Optimax is guaranteed to be a minimum figure, even at the pump. Tesco's is a manufacturing figure which by their own admission will differ at the pump.

The Tesco stuff used for motorsport (which it is pushing by advertising) is made specially from one batch so its consistant. It has to be ordered in advance. That tells us all something

 

Thing is though, do they? I've heard everything from Optimax having a v short shelf life and by the time you buy it in some circumstances it's below that figure to BP being the most stable out of them all. Does anyone ACTUALLY know or are they all basically the same

 

For 90% of people they are all the same I guess.

For the other 10% there is a vast difference

 

Genuine un-photoshopped picture from the Rally of Wales, whilst its subject topical

 

i dont use tesco at all now for some reason i found there fuel dont last as long as using the others (super,etc) might be just bollox im talking but just seemed like it too me and i used it a few times

 

Did this car survive that jump

 

As Tony says.........to confirm this, Tesco are offering sample 99 RON fuel for mapping your rally car to (see advert below).....and it's described as a "control fuel" so it cannot be the same as at the pumps

 

they did a test in performance ford a while back and they said the same sort of thing
1, optimax
2, ultimate
3, tesco

mind you, each of the cars were mapped to run the best they could on the fuel they had in their tanks, and best to worst was in the region of about 40 brake

 

Does anyone have a scanner to get that topic up on here

 

Aye, thats only a minor off, It was re-panelled up. It's the 2nd car you can see in Doug's press article The red one however had to be reshelled I think after a similar bigger accident last year.

Interesting how both cars wanted to be No 1 for the photo shoot