I've been filling up with Caltex 91 (non-ethanol) simply because I had those fuel vouchers.

The past couple of tanks I used Shell 91 (again non-ethanol) as I had some vouchers (16c/L off) and my car seems to run smoother on this.

Can anyone comment on what fuel they find their car runs best on?

BP 98 is the only fuel in mine. Being a duel fuel car, petrol doesnt get used lots.


I also use BP LPG as well as their co branded 'on the runs' as its the same fuels.

Have tried other outlets in SA, but find the LPG burns faster compared to BP and my economy suffers.

Dont worry about vouchers, after all, a 4c off per litre voucher will only save you a maximum of $6.

the cheapest E10 petrol i can get my hands on. really makes no difference in magnas, in my experience (having owned a few now).

98 for me

Mine runs better (seems to me) on BP98 then Shell 98 or at a minimum the Caltex 95 - I don't use anything else as the mileage (kms per tank) is about 50-60 less on the 91, and appears smoother and goes better :)

I noticed I get about 50kms less on 91 compared to 98 as well but the added mileage does not offset the added cost.
I try to run 98 every 5th tank though, not sure if this helps in any way to keep things cleaner?

I mostly run 98ron also. Gets more ks and feels more responsive. If I'm broke I run 91ron.
Just as a point of interest when I worked at a refinery I noticed the propane/butane ratios of LPG changed on a daily basis....

A note to other LPG owners.
Do not use high octane fuel!
The light weight esters that boosts the octane rating boil off over the course of a week or two (depending on the weather) leaving you with a fuel that is no better than regular, or sometimes even worse.

This advice comes from several different sources, including several motorbike mechanics that have run into this issue before. The fuel in a motorbike is subject to more warming than a car, and the effect is quite noticeable in my mates FJR. That bike has quite aggressive timing, and when run on premium fuel, runs great - for the first few days, after that it starts to ping.
When run on regular fuel, no pinging, usually. Sometimes on hot days it will ping a little, but nothing like a few day old premium fuel!


So, those of us penny pinchers on LPG - don't waste the coin on the "good stuff" and stick with the regular fuel. The ECU has a knock sensor and will adjust timing depending on what fuel it's running. Or at least mine does.
A full tank of gas, flick to petrol, get some light detonation the first time I give it WOT from standstill - after that, no detonation.

No knock sensor on the third gens, I think.

I use E10 often, have noticed no problems on my stock TJ and TL, but then WOT starts or WOT 1-->2 shifts are a no-no. (Why risk breaking it? lol)

Both LPG and petrol can vary in mix for both production and climatic reasons.

I'm interested in all the people saying that they use 98 RON in their third gen Magnas. Along with MadMax I also thought that third gens lack a knock sensor and therefore the ability to adjust engine timing depending on how refined the fuel is.
For those people using 98 and claiming a 50km range advantage, is your engine stock or has it been retuned (ECU flashed) for 98?
Please enlighten me.

"A note to other LPG owners.
Do not use high octane fuel!"

I wasn't aware that you could get high octane LPG, but even if you can, there is nowhere for the lightweight esters to boil off into - the tank is a closed system.

Another point to note - if you live or drive at higher altitudes, you can get away with a lower octane rated fuel without the engine pinging. I found this out years ago when I had no option but to use standard petrol in my 10.5 to 1 compression Citroen. It ran fine at altitude (800m +) but at sea level rattled like a machine gun. Engines always run better at sea level.

For those people using 98 and claiming a 50km range advantage, is your engine stock or has it been retuned (ECU flashed) for 98?
Please enlighten me.

No I have no retune, just stock and with 98 octane it gets further mileage. Oddly the average fuel consumption computer shows the same figure though

I'm interested in all the people saying that they use 98 RON in their third gen Magnas. Along with MadMax I also thought that third gens lack a knock sensor and therefore the ability to adjust engine timing depending on how refined the fuel is.
For those people using 98 and claiming a 50km range advantage, is your engine stock or has it been retuned (ECU flashed) for 98?
Please enlighten me.

While I didnt claim to get better milage, I use 98 because I had one bad batch of fuel before, and it was a pain to resolve the issue. Never again. I use 98 BP because its ment to be better than the rest.

Trust me, draining a full tank of fuel, new fuel pump, cleaned injectors, oxygen sensor and a few other bits and pieces was enough to warrant me never using 91 again.

Rush, what makes you so sure that this can't happen with 98 octane fuel?

Rush, what makes you so sure that this can't happen with 98 octane fuel?

Nothing, but 98 is hyped up as being a much cleaner better fuel compared to 91 so ive figured id listen to them.

Also, as mentioned, a tank of fuel would last me 6months because I mainly use LPG. I only keep 1/4 a tank normally of petrol, but i figured it might help it not go stale having 98ron in it

Mines stock (I've had it since 2000 when I got it at auction - ex gov with 21k on it - so figured it hasn't been modifed). My mechanic noted that he could tell I only used 95RON (I don't know how?). It seems to drive better to me and and I get about 600km from a tank, once when I used 91RON I got 550.

On current prices (today in the ACT) I've done a little analysis below - (not that accurate as the ranges are not exactly 50km difference in the real world). When fuel was cheaper I did this to decide to use 95 only. I had noticed that the recorded fuels consumption was better as well.

Price 155.9 165.9 169.9
litre 68 68 68
$ 106.01 112.81 115.53
range 550 600 600
$/km 0.193 0.188 0.193

Realise this is in the 3rd gen forum, but since I have a 2nd gen, and a third gen, the third gen (1997 altera wagon 3 litre) seems to run find on 91 ethanol, its just smooth on it for some reason, my 2nd gen is tuned to 98 and I run it on strictly shell 98, tried bp and caltex, actually got bad petrol from caltex so I stick to shell

Price 155.9 165.9 169.9
litre 68 68 68
$ 106.01 112.81 115.53
range 550 600 600
$/km 0.193 0.188 0.193

I think the price per liter for 98 is $1.78 or so though isn't it?

I think the price per liter for 98 is $1.78 or so though isn't it?

Got the prices from http://motormouth.com.au/pricesearch.aspx today (filled up last week - but wouldn't be surprised as this is Canberra)

I find not difference in power or smoothness between 91 or 98.
I do however find massive difference between woolies 91, ANY E10 petrol and BP 91.
So, I just use BP 91.
Those fuel vauchers are crap, only saves you 40c every 10 liters you put in, so $2.40/60 liters.. Is it really worth it?? not in my opinion unless you fill it with 100 litres of premium fuel. (thats a cup of coffee at the cafe.)

"A note to other LPG owners.
Do not use high octane fuel!"

I wasn't aware that you could get high octane LPG, but even if you can, there is nowhere for the lightweight esters to boil off into - the tank is a closed system.

Another point to note - if you live or drive at higher altitudes, you can get away with a lower octane rated fuel without the engine pinging. I found this out years ago when I had no option but to use standard petrol in my 10.5 to 1 compression Citroen. It ran fine at altitude (800m +) but at sea level rattled like a machine gun. Engines always run better at sea level.

Not high octane LPG, but rather the 1/4 tank of petrol you have sloshing around for weeks, if not months!

Same old bs comments. FFS high octane petrol does not burn "cleaner", it does not have more energy , it does not clean your engine. Manufacturers claim to add additives that "clean", truth is all petrol must have cleaning additives = simple. Magna's have no knock sensor, thus ecu can not advance timing to take advantage of higher octane. Higher octane means = higher resistance to knock, THATS IT! NO magic to make your car more powerful or more economic without ECU making adjustments and in a Magna it can not . Dont confuse 91 with 91 which has 10% ethanol, ethanol has less energy so you will burn more of it. You are wasting your money, if you are really concerned with your fuel system being clean then add cleaning additives yourself every 5th tank or so.

98 RON always.

straight 91ron w/o ethanol because as some have said magna's cant take advantage of a higher octane fuel without a re-tune.
i have used 98ron on a highway trips before but got no noticeable increase in mileage so i usually just stick to 91ron now.