Fuel

[EddyEdwards]

What fuel am I supposed to run my BG on? I've tried RON 91 and RON 98, the car feels considerably healthier on RON 98, but the power difference isn't really noticable if there is difference. It's a 1990 BG Astina, was it ment to run on premium intially or what? It certainly feels happier on premium...

What am I supposed to be putting into the little guy? If premium doesn't hurt it any I think I'll perminantly change to it :P

[mill_mobile]

Hi,

I am by no means an expert on this sort of thing, but from what i understand no matter what you have if you run premo through it it will run better.

I think its just the $$factor why lots dont stick to it.

J

[project.r.racing]

95 ron

[Cosmo Dude]

Your car is designed to run on normal unleadad fuel, sorry end of story save your self the extra 10-12 cents a litre 'cos Optimax just isn't worth it.
Test:
Start a book, record the Km, the amount of fuel, the price of the petrol and the price of premium petrol.
Run your car on standard unleaded for 6-8 weeks.
Run your car on premium unleaded for 6-8 weeks.

Now you can calculate the benefit of a higher octane fuel.





I ran the 929 on Mobil 96ron, the mathematics told me to.

[Astro Boy]

but from what i understand no matter what you have if you run premo through it it will run better.

I hate to say it, but that's about as un-educated as you can get...

Go get a 1980's small capacity carby sports bike, run it on BP ultimate, then count down on your hand the number of k's you get till the thing dies of fuel starvation, or worse throws a let out of bed through running lean...

I really can't be arsed tonight going into the reasons why (its starting to get like the oil argument, and only ever comes about because people don't bother searching the forums first), but run your car on 96/95, preferably Caltex, BP, mobil, daylight, moonlight then Shell..

Avoid high octance fuel in any generic pos unless otherwise tunned for it...

[Astro Boy]

ok, i'm feeling generous, here's a post i made on another forum a coupla months back..

For Brisbninites...

Any 91 or 95 you buy at shell, bp, mobil is refined at pinkenba here is QLD, and is the same regardless of the servo, they do alot of trade swapping north/south to save extra piping across the bar ... that's not to say they're the same fuel, because often companies will add stuff after the fuel is processed...

All 98 octance fuels are made by the servo selling it, Shell bring it up from Vic, BP make it here in QLD (as well as WA), and Caltex bring up all their fuels from NSW...

As for which one, well, BP Ultimate is the control fuel for the lower spec australian rally championship, and unless you have to run it, you don't. I've got a mate who's actually a chemist for BP and co-drives in the QLD championship, and they run Caltex... To me that says something... BP ultimate isn't consistent to tune to, and has already accounted for a holed piston in this championship. For example, BP not long ago over produced 95, so they added an octane booster and sold it as ultimate, where generally their 98 is processed at 98... two different fuels, both sold as ultimate...

The other problem with regular ultimate is that its too high in aromatics... Unless a car is very highly tuned, it can't get the best out of it. Carby cars hate ultimate, as do motorbikes, because its too dense...

Personally, I'd be going Caltex 98 now that its avaliable up here, 96 is great, and for your average car that can't retune itself, will actually run better. You want the highest octance that your car can tune itself to. Running a too higher octance will decrease power as octane actually makes fuel burn slower, and unless you can advance your timing to suit, you're loosing out...

Regular Shell is ok, optimax is rubbish, inspite of what all the v8supercar ads will tell you. Optimax Extreme with its 10% ethanol probably isn't as bad as you'd think. Most modern cars will accept 10% without a problem, and holden even released a white paper saying it didn't have a problem with it. Remember too that holden has great experience with ethanol as they export commodores to mexico where the fuel is 100% ethanol!!! They use copper fuel hoses and few other bits and pieces...

Mobil's good, nothing terribly flash here in QLD cause we dont get the premium range, but they're a good consistent fuel that shouldn't cause any problems..

And as for this "oh, i buy aussie fuel bla bla bla" crap... alot of crude oil comes in from overseas, but 99.9% of it is processed here... the difference is that the ONLY one that keeps the profits here are CALTEX/AMPOL... BP/SHELL/MOBIL are all wholely foriegn owned...

For me in QLD, its Caltex 96/98... Aussie owned, by far the best fuel, and if you're really that anal, 4c a litre off for shopping at woolies... Every car is different, and depends on what you've done to it... For example, I run both my tarmac and dirt rally cars on Vortex 98, but run my VZ AWD Commodore on Vortex 96 cause it runs better on that...

[chicaboo]

Expanding on Greg's comments: my car tends to retard when I run the 98ron fuels. If I really get into it, I can even feel the ignition retard up around 5000rpm before VICS kicks in, it will develop a power flatspot even more pronounced than usual.
95ron seems to the most healthy fuel for my car, and it seems to work within the limits of my stock ECU without throwing money away for no reason. However, my car feels like crap even moreso on 91ron fuel, but then I have I/C/H/E mods, so the 95ron is probably about what it likes.

Gav.

[EddyEdwards]

Cool thanks for that, I had a brief overview of the threads but yeah, too lazy even still, thanks indeed for what you guys have posted, I love your generousity Astro

[Melbastina]

Yeah, I've been testing out a few of the fuels using a spread sheet and am getting no significant differences. The car seems to run better on 98 (probably placebo affect), burns more of the 91 stuff, 95 seems to be a good compromise.

I was/am considering switching back to 98 and getting the timing advanced (don't really know if it's worth the trouble) and have been told to do it using shell 98 not ultimate because of batch reliability...

Again, thats advice I am taking with a grain of salt, any advice from experienced BJ owners (you know who you are) would yet again be greatly appreciated.

[Astro Boy]

The biggest problem with Ultimate is its too high in arimatics, and thus too dense, and unless other wise tuned for it, suffocates engines, or in the case of quad carby's on a small motorcyle, won't actually get through!

Optimax's problem is consistency, and the fact that they use a dodgy additive to boost it from its manufacturered 95, on the OTHER HAND optimax extreme is EXCELLENT, and has only been added to servo's that haven't had a history of water contamination, which is a BIG STEP foward on Shell's behalf. I continue to hear excellent reports about the consistency and power acheived out of it. Even so far as probably one of australia's best engine builders (the guy who built the Targa Tas 04 WRX winning engine) has come out and said he can get asmuch power consistency out of it as $7/L ELF WRF...

Once again, great if you can tune for it, a pain in the arse otherwise...

Which brings me back to only one choice, Caltex, premium fuel, excellent fuel consistency, and australian owned, albiet partly, which is still more than the others, and if you shop at wollies, a BONUS!

Speaking of which, if you had a fuel voucher in brisbane today you could buy fuel at $1.00 a litre!

[chicaboo]

Caltex Vortex 95 is my poison of choice!

[mazdamanik]

ive been doing some testing also and found that in my 92 bg, 91RON burns faster, 95RON runs smoother, has a slight increase in performance and i get 650km to a tank (rather than 600 with 91) and running Vortex 98 dosnt make a scrap of difference over the 95 that i can tell....so for me my 92 BG runs best on 95

[Astro Boy]

Caltex Vortex 95 is my poison of choice!

As is mine!

When a mate of mine who works for BP tells me to run Caltex, that's all the convincing I need!

[mazdamanik]

Vortex premium is Vortex 95 right?

[Astro Boy]

Caltex:

- 91 'Unleaded'
- 96 'Vortex'
- 98 'Vortex 98'

[mazdamanik]

righto kool thanks astro, Vortex is wat i use so yeah i find thats the best for my car

[chicaboo]

Originally Posted by Astro Boy

As is mine!

When a mate of mine who works for BP tells me to run Caltex, that's all the convincing I need!

I only came to that decision from trying different fuels over several months, and not just going off what some fanboy told me. But that is what works for my current car, or atleast as it runs now.

Meh, you can always shop at Woolies and get 4c off too. Oh yay, feel the excitement...

[platypus]

the astra has a switch under the bonnet apparantly to switch the maps.... sweet huh?

yes gregs right.... go 95 tis a sweet fuel,

but i still disagree with the ethanol... i used to lose about 100-150km a tank with it... but you should do your own tests as your car is different to everyones here...

[Astro Boy]

I never said ethanol will get you more k's, and it shouldn't given its specific energy is lower than petroleum, but if you want outright tuned power than you can't go past it...

[HI-RES]

My experience on my BJ I prefer Shell Premium 95, followed by Ultimate, followed by Vortex 95.......on the latter I used to get alot of inconsistency in the fuel, sometimes sluggish sometimes smooth, but I wonder how much if this could be attributed to near empty bowser tanks (i.e. sucking up the impurities), and genuine inconsistent batches (?)