Optimax, Vortex and Ultimate
 

I read this article in Royal Auto (or something similar) saying that Optimax wasn't worth the additional cost - the additional cost was not worth the cost saved (fuel efficiency wise).

The article indicated that 95 was the better fuel to go for. I spoke to a friend and he said my car (Astina BA) is designed for 91, and I should stay away from 98, in particular Shell Optimax because they just add the extra octane. Whereas, BP Ultimate, the extra octane is designed into the fuel (or some **** like that).

What do you guys use?

I get around 450km on a 40L tank in my 1.8L BA on optimax. As my low fuel gauge is alight, I was thinking I'll put in BP Ultimate or Caltex Vortex (95)...

Any recommendations?

There is another string where this has been all argued before its the Shell
100 octane thread. My car was dyno tuned on Optimax 98 last year as the
servo was close to the tuner and I needed juice. Now Optimax 98 or 100
pings but Caltex 95 doesn't so to me its ****. I now force myself to shop
at woolworths to get the dockets and now run Caltex 98 for the same price
as what I was paying for 95 ie -4c. I like BP but they dont discount so same
98 vs 95 logic there.

95 does the goods for me, V6. Both BA engines where designed for 91.
Not sure if it pays for its self, but it never pings where 91 did occasionaly.
I do getmore KMs out it.


NRMA open road did a thing on various fuels saying that going higher RON does not = power or even more KMs, what the RON number indicates is the fuels Anti Knock properties. So running 100 in anything but a luxury euro, a really sport jap (Evo’s etc) or with a car with a remapped ECU is waste of money and will not get more power. The reverse however if you run 91 or 95 in something designed for 98-100 you will lose power, KMs and eventually probably the engine. So it would seem my car has deicded it wants a higher RON for some reason (age and a bit of wear and tear) so I get better power and KMs form 95.

In cars designed for 91 I have not heard of anyone who regularly uses 98 or 100 and thinks it is good value.

Chicaboo (Gav) dynoed or atleast did a bit of testing and lost power with 100 against 95.

I used to get significantly better fuel usage from using optimax in my old camry, I got between 60-80KM/tank extra compared to regular unleaded.

That to me was worth the extra couple of cents even if I saw no power benefits (there were no noticable power losses either).

I run regular 91ron in my astina because I found that optimax/vortex etc just cost me more and did nothing else.

i use vortex95 from caltex and get 550km per tank (highway and city driving.) probably your bext fuel saving mod would be to up the amount of air that foes though the engine = power + ecconmy!!!

The thing with added stuff to Optimax is the benzene they boost if up with, which is allowed at higher levels in eastern states but I've heard they are going to crack down on that. There are uni studies here in Oz that suggest the higher levels of benzene damage bits of the engine over time, and its nasty carcinogenic stuff....so pick BP MObil or Caltex which don't use it...or not at as high levels.

i use 91 or whatevers normal cause its cheap and so am i :P but im thinking i should try some reallly good stuff in my bg sp to test the fuel economy (i drive 30mins on a highway to uni)

i used to use 98 when i had a full time job, but didnt notice heaps of difference (slightly more kilometerage if anything..)

Not quite, the stock (BJ) ECU adds more fuel when it detects more air. This isn't a problem if you have a hiflowing exhaust to reduce the restriction on the other side of the engine, but drastic on economy if you don't... Arden and I both have the beautifully quiet XForce twin-loop muffs now, but that exta restriction that keeps the noise down, also spoils fuel economy somewhat (still better than stock). But it's worth it not having to hear the damn droning anymore!

RULP 91:
Ordinary power and reasonable fuel economy for me...

Optimax 98:
I get reasonable performance, not much better fuel economy than with 91.

BP Ultimate 98:
Car runs like a slug, feels worse than running 91, decent fuel economy.

Vortex 98:
Reasonable power and economy, better than all of the above.

Vortex 95:
Exactly what my engine craves! Very good power AND economy!!!



Gav.

i tried shell 95 octane. first fill was 40 litres and i got an extra 50 km. the next time economy was up the creek again :s

Yep, Vortex 96 is the go! Although i'm having a chop at trying to tune the rally car to fully sik Opticrap Extreme, i'll let ya know how it goes.. pretty much stay away from normal optimax, and unless you tune your car to use it, stay away from 98, and use Caltex 96... i know the majority of my mates in southern states use caltex 96 or if tuned for it, caltex 98 in their rally cars, and it seems to have the most consistent mix...

I use BP ultimate 98 because I have a japspec engine.

Back when I had my NA engine I ran vortex 95. It worked rather well.

Is there a GTX engine that isn't Jspec? Maybe someday I will try BP 95...

yes. the engine is the same but the computer is different - the JSpec is tuned for Japan's standard 100ron fuel , the aussie version is downtuned for our crap petrol

I used to run 95 (usually BP) but lately my car has been running like rubbish on it, I gave it a couple of tanks of ultimate and it's come good again....

Odd this one, i usually use, optimax, after reading a number of recent posts started experimenting. Found 95/6 vortex was fine, but BP felt like ****, across the range (95-98) car ran noisy, engine wasn't smooth, lost 80kms per tank. Go figure. Next tank i'll try vortex, maybe try 5 or 6 tanks of that otherwise can't really tell.