BP Ultimate and Shell Optimax

[C240Sport97]

Do people use these premium fuels?

They are about 6p per litre more than normal unleaded and about 8p per litre more when compared to Tesco normal unleaded. Is it worth it?

I put it in the car tonight and really can't say I noticed any real difference.

 

[uumode]

Do people use these premium fuels?

They are about 6p per litre more than normal unleaded and about 8p per litre more when compared to Tesco normal unleaded. Is it worth it?

I put it in the car tonight and really can't say I noticed any real difference.

The results depend on different engines from reading other forums, also some cars run better on one or the other.

Ultimate in my Audi 90 made everything silky smooth and the engine ran quieter with a bit more oppmhh. This is being critical and being very aware not to fall into the placebo effect, where you 'think' it's better cause it cost more.
However I found different batches of Ultimate were different sometimes the difference was not that noticable, but on the whole it was.

Optimax on the otherhand made my Audi very noisy and rough but because of the higher octane it gave more ompph than Ultimate and boy... it felt like a 911, so much more acceleration. I suppose similar to dumping a load of octane boost in the tank.

They say it needs about 5 tankfuls before you notice the difference as your fuel system is flushed out.

It is expensive, not worth it if you don't need that extra performance, but it supposedly burns much cleaner with less deposits so the engine lasts longer.

I currently have the first tank of Ultimate in my Polo there is a slight peformance increase, engine is slightly quieter when revved, have to see how it goes.

I haven't put any premium fuel in my Merc as it's already quiet and smooth enough and the performance is fine. Though I might put a few tankfuls in just to clean out the fuel system.

Fuel consumption wise I didn't notice much difference the same or only 1mpg more...quite negligible on that front for me.

Though I guess the real blind test would be to see if the wife notices it! (without telling her)

 

[Robby]

My old golf 1.3 used to like optimax. It was a total dog, but the combination of the better fuel and weber carb made it fun in a slidy way.

Escort liked ultimate, felt smoother with a bit more oomph.

Merc.. I never need to use all of the power, and its very smooth on normal fuel. If I was to use high octane fuel I'd adjust the trimming plug on the FI system to take advantage.

 

[stwat]

Merc.. I never need to use all of the power, and its very smooth on normal fuel. If I was to use high octane fuel I'd adjust the trimming plug on the FI system to take advantage.

Trimming plug? FI system? Adjust? What? Who? Where? Please fill me in!! what and where is the trimming plug??? And how do i adjust???

 

[Ian B Walker]

From the front of your car look at the right hand side of your engine bay. Looking backwards you will see the Ignition gizmo thingy and behind that is another block / plug with numbers on it. I think that is the trimming plug mentioned although I may be wrong.

 

[stwat]

When you say the ignition gizmo, do you meen the big silver brain right at the back near the bulk head??

 

[Ian B Walker]

Nope the TSZ or EZL Electronic control unit. If you have a Haynes handy there is a picture of it on page 5B*6

 

[stwat]

I have a haynes but its for the mk1!!!! But it does show a pic of the engine bay. Is it the ignition system electronic switching unit? On the right hand side next to the coil?????

 

[Ian B Walker]

yes thats the one, now look close by and there you will see a plug with numbers on it. I "think" thats what is talked about. I was never brave enough to fiddle with it though.

 

[stwat]

Thanks for that Ian But like your good self, i dont think il be medaling with it!!! Id probably set the engine up to pink its self to death or something LOL.

 

[PJH]

...... I was never brave enough to fiddle with it though.

Mine has got 'Security Wire' through it so that mortals don't fiddle with it.

I have used both Optimax and Ultimate prior to MOTs, just to be more confident of passing the emissions test.

 

[uumode]

Merc.. I never need to use all of the power, and its very smooth on normal fuel.

Yep, same situation, don't feel the need.
.

If I was to use high octane fuel I'd adjust the trimming plug on the FI system to take advantage.

Never knew that, on Audi it is 'automatic' or so I was told. So when throwing in a different octane fuel, the first 100 miles or so it is readjusting itself and feels a bit rough and gutless, then it smooths out with more power.
could be placebo effect of course

 

[Shude]

I found that my c230k works best on ordinary supermarket petrol, which in the end is what it was designed to run on

 

[Satch]

Fuel quality can make a huge difference but only if the engine is fully capable of adjusting itself or being adjusted to take advantage.

Optimax works well in my (soon to be gone) V6 Vectra because it has an ECU and knock sensors capable of shifting the ignition timing. It runs smoother and really does pull a lot better. Even my wife notices the difference and normally the wheels have to fall off before she picks up on things mechanical. But it is equally true that in many cars it seems to make little difference.

Run a E320Cdi on BP Ultimate and it does make a difference. Maybe not a huge performance uplift, but it is smoother and less of a "diesel" noise at tickover & low speed. One load of indifferent fuel shows that up very clearly

And just to make the point, there are a lot of funny fuels used in racing and by some Skyline/Evo owners who have read too many editions of Max Power.

See "Racing Fuels" in the product section.

http://www.76andr.co.uk/frameset.cfm

 

[Alps]

I normally use optimax, as alot of places have stopped selling super unleaded!

i used bp ultima once, and it did have an improvement on optimax!

 

[steptoe]

don't touch the stuff, i remember the debacle from the mid eighties with people using "formula shell " , it started wearing out engines, especially BMW and vauxhall , it cleaned engines very efficently, it was taking the film of oil off the cylinder bores, shell had to stop selling it.

Don't get fooled again

 

[C240Sport97]

hard to know whether an extra £3.50 or so per tank is worth it ...

it looks as if it's not merely marketing hype .. however, the biggest difference in performance is how heavy you are with the accelerator.

I can't tell the difference in the V6.

 

[guydewdney]

my cl does almost exactly 400 miles to a tank on 'regular' and 440 miles on super..

10% increase in fuel economy, repeatable, for 5% increase in fuel price (usually)

 

[Chrisboz]

One thing I do no about this is that BP have not brought out a new fuel with ultimate, its actually their bog standard super unleaded with a double dose of BP additive in it, Shell optimax is complete new blend to replace their super unleaded, has no additive put in like other fuels as already blended as complete package! optimax is only produced in main refinery at Stanlow, its available almost everywhere because other terminals have to collect from Stanlow on night shift then milk-round it to the garages the next day, I know cos I deliver it, BP drivers say their lot brought the ultimate out to compete, diesel extra & pura are basically same as well, different amounts of additive but same basic fuel really!

 

[Mark300SL]

Both of my Race CRX's run exclusively on Optimax and millers octane booster, and Optimax does allow more power to be made on the dyno.

Ultimate is rated at 97ron bit optimax is 98ron.
Only buy Optimax from a busy garage though as it has a shelf life which is measured in weeks due to the very complex and volatile additives.

Mark