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Guest two.06l

over the last 3-4 months i have noticed a decline in the quality and consistency in shell optimax fuel.just switched to mobil sygnergy 8000 and the difference is unbelieveable.Able to run more timing and boost without a hint of detonation has this stuff been kept a secret or am i just ignorant of its existence or use.

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https://www.sau.com.au/forums/topic/38750-optimax-fuel-quality/
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It was proven many years ago that optimax was only good for 2 weeks... Before its oct whould drop down to around the 94-93 mark... Making it about the same as regular....

It would be impossible to get pure fresh optimax.... Unless you work for shell and are getting it straight from the 500million litre tanks.......

I noticed the same thing at Eastern Creek on Monday. Took the car for a spin with a tank full of BP Ultimate. At around 3pm I went out to refill at the nearest petrol station (Shell). Went back to the track with exactly the same car settings for a couple more sessions. I noticed that it was running roughly. I couldn't think of anything else other than the Optimax causing this.

while in adelaide i always used bp ultimate, as we dont have optimax. Mobil 8000 isnt as common in SA and we have the idea that it doesnt get much of a turnover so we dont really use that either. When i first brought the car up to sydney i filled it with optimax and i certainly noticed less power plus it just didnt run as clean or strong. So far havent been dissappointed with ultimate.

whats the bottom line with fuel going "off"? in my understanding that would be dropping its octane level. Ive heard that sitting for even a month or 2 can have it go down. Where does this 1 year thing come from?

optimax is a molecule expanded fuel that means they start with 92 ulp and play around (wont go into details, boring stuff) and make it reach 98... whereas mobile and bp fuels are initially refined to 98 octane they are not expanded... thus optimax is more unstable on a molecular level and more vunerable to chemical reactions such as reactions with oxygen, which is evident in the tanker trucks that trasport fuel and even in your fuel tank... optimax thus will only last a month max in your tank before significantly degrading itself...id expect bp to last 9-12 months before the same processes. bottom line optimax is way crappier, but is good if you use it straight away and it freshish off the supplier..

Yep noticed much the same as everyone has previously stated. I had, and I do mean HAD to fill up, and the only fuel that was around was optimax, didn't want to use it but yeah nothing else around, so I decided that I would only put $10 in just to get me to where I knew the next BP was. And I swear that 40min drive was so shitful, the car almost stalled so many times coming up to lights and just ideling at the lights, couldn't work out WTF was wrong only conclusion that I could draw was that the change in fuel didn't agree with my car and tune. Filled up at BP, full tank still ran like a bag of shit for another 15min then cleared up and was sweet. Never using optimax again.

I filled up Optimax only whenever I got that 4c dicsount coupons from Coles (being dirty old, tight ass Thursday petrolhead :)) Shell is on my way home from work

When I have no coupons I went a bit further down the road (100m) for BP Ultimate....

Never pay attention to any differences between the two, but I use up a full tank of Optimax in around 7-10 days anyway so may not feel the effect of the fuel going off before the next refill anyway. Car is my daily driver to work and my shopping cart too.

Also, I found km per tanks is not a difference between BP & Optimax, just a matter of how heavy my right foot is. Turned off my boost controller (stock boost) and drive below 2500rpm since last month, now I refill every 10 days instead of 7 days as I used to be.

Hey, more $$$ for future mods :)

i once used the octane booster, car felt much more smooth

..

Some brands of Octane booster is known to cause your plugs to foul, causing it not to perform 100% and may lead to engine damage in the long run.

I would stay away from them, unless I really have to use it, e.g. in the outback where no premiums available.

yes, shell is crap. bp is the gear.

imho,

shell opticrap < mobil synergy 8000 < bp ultimate

:werd: Altho I've never been able to notice a more than negligible difference between Mobil 8000 and Ultimate. For some reason I prefer Ultimate tho.

As s13drifter began to explain, the reason to stay away from Opticrap is the fact that they achieve the 98 octance via the use of additives which expand the molecules, rather than refining it for a 98 octane.

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