Iv always ran my car with 98 Ron thinking that it gives my car a little bit extra power.
Then when i finally got G tech pro fanatic i decided to see if there was an actual difference.
Thought you might be interested in my findings.

Firstly i drive a TJ Magna Sports 2003 model its an automatic with about 120 000kms on the clock
the mods i have had done was full exhaust from redback (including high flow CAT and extractors) i have also put on a streetfighter manifold

My best times are the following
91 Ron (full tank) 7.63 0-100 15.45 Quarter Mile
98 Ron (full tank) 7.52 0-100 15.33 Quarter Mile
98 Ron (almost empty) 7.29 0-100 15.22 Quarter Mile

All the runs where tested on the same stretch of road at nigh with around 8-12 degrees
When i tested the 91 Ron times how ever the road was half wet and i couldn't get anywhere near as good grip as with the other times i tested the 98 runs.

So I have come to the conclusion its a waste of money filling up with 98 Ron for any performance gains. Unless ofcourse you have had your Magna tuned for 98 =)
ps If your interested in what speed i finished the quarter mile times in let me know and il check =)

Orly???

orly??? want to expand on that lol

An almost pointless test. The magna as standard has no sensor to detect and advance timing, therefore more engine power with higher octane fuel is impossible.

However, the premium fuels do have more additives than regular 91 and help clean the internals to an extent, as well as creating a cleaner burn. Your economy may improve slightly but not performance.

I've always found Premium to deliver better overal economy as well as less egg smell due to a less build up of sulpher which is more higher with Unleaded as I've been told. Either way I use it for non performance reasons.

what your saying is true Dave but we all know that sometimes logic on paper doesnt necessarily equate the same results in the real world thats why i thought i might test it and post my findings =)

No knock sensor means no performance gains. I stopped using it because its too damn expensive. I run a bottle of injected cleaner through it every now and then. That's all the cleaning I need.

what your saying is true Dave but we all know that sometimes logic on paper doesnt necessarily equate the same results in the real world thats why i thought i might test it and post my findings =)

Not having a knock sensor isn't exactly "logic on paper," it is the lack of a feature which allows a cars ecu to advance timing to take advantage of the higher octane rated fuel. Even the addition of cleaning agents to the fuel has debatable benefits, but if people want to pay 15c extra for their fuel, just to feel warm and fuzzy about "cleaning" their engine internals, they're free to do so.

But don't get me wrong mate, kudos to you for putting in the time and effort to test your theories and provide actual evidence.

orly = "Oh, really?"

Yep - it was always believed here that there would be no performance gain, and you've basically proven that. More interesting would be a repeat in the same dry conditions for the 91 ron fuel. WOuld it shave off that 0.1 second difference, or even better it?
91 fuel is more volatile than 98 - 98 is more stable, hence more resistance to pinging. Maybe the Magna is finely tuned for the 91 and people shouldn't be messing with what MMAL spent thousands of cents researching and perfecting. <-- trolling intended, sorry couldn't resist.

I'd still like to see if fuel economy is better from higher octane fuel.
I think it is - I get about 8% better fuel economy on 95 Ron than 91, but it costs 10% more. So unless it's in my brain that the fuel cost more so I should drive gentler, then theres some type of efficiency improvements that simply don't result in more power.

Even if you did the tests on a car with a knock sensor you wouldn't see HUGE differences in times and it would need to be repeated numerous times to become reliable anyway. Just putting that out there but good work doing the testing lol, woulda been fun :)

The knock sensor doesn't advance timing, it can only delay it if it senses detonation. (as far as I know)

I wonder how low you can go below 95 octane before the pinging becomes a problem?

An almost pointless test. The magna as standard has no sensor to detect and advance timing, therefore more engine power with higher octane fuel is impossible.

However, the premium fuels do have more additives than regular 91 and help clean the internals to an extent, as well as creating a cleaner burn. Your economy may improve slightly but not performance.

Spot on Dave! Make's no difference performance wise but much better for your engine. ;)

OP, 0-100 times and 1/4 mile times can change like underwear and are dependent on a myriad of factors. You would have to complete 100's of tests on various vehicles using varied fuel types to come to a conclusion of performance gains.

98 Octane is only value for money if you get your car dyno tuned for it. You will get more power and you will save fuel if your right foot is not made of lead.

98 Octane is only value for money if you get your car dyno tuned for it. You will get more power and you will save fuel if your right foot is not made of lead.

Since my car was tuned for 98 it is much more efficient when i drive with a heavy foot tbh.

However, the premium fuels do have more additives than regular 91 and help clean the internals to an extent, as well as creating a cleaner burn. Your economy may improve slightly but not performance.
Some might argue performance is slightly better because of the cleaner freer flowing internals. Any possible outcome of that though would likely just be placebo.

The knock sensor doesn't advance timing, it can only delay it if it senses detonation. (as far as I know)

I wonder how low you can go below 95 octane before the pinging becomes a problem?


Pretty sure you could go down to 91 octane without any issues.......Don't you think? lol lol

Since my car was tuned for 98 it is much more efficient when i drive with a heavy foot tbh.

Same here. The 98 tune increased my overall rpm kw and torque while being significantly more efficient.

Where is the independent research that says the additional detergents in 98 are that much better for your engine? I'm not saying that it's incorrect, just wondering if anyone can actually back up the claim.

In my old untuned car it always felt better like the car fired more smoothly. Placebo affect or not i was happy so it was worth it lol

I put my 380 on lpg, about 50k km later cel came on. turned out that the injectors were gumming up. Put a trade quality cleaner through it and from then on have only used 95, 60k km since then and no more gummed up injectors. So premium fuel has it's positives.

I put my 380 on lpg, about 50k km later cel came on. turned out that the injectors were gumming up. Put a trade quality cleaner through it and from then on have only used 95, 60k km since then and no more gummed up injectors. So premium fuel has it's positives.

This is true. However, there is a way around this. About once or twice a week, I give the engine a good rev (full throttle) taking off traffic lights in a 80 zone. (If i am lucky enough to be in front). This cleans out the carbon build up. Even something as simple as taking it for an interstate drive would do it.

I have only used 91octanes since new. never used any fuel treatments etc.

This is true. However, there is a way around this. About once or twice a week, I give the engine a good rev (full throttle) taking off traffic lights in a 80 zone. (If i am lucky enough to be in front). This cleans out the carbon build up. Even something as simple as taking it for an interstate drive would do it.

I have only used 91octanes since new. never used any fuel treatments etc.

Are you on LPG?

Nah, tried all that. Once the injectors are gummed up you have two choices, take them out and have them ultrasonically cleaned or use a proper injector cleaner, one used by the trade. The premium fuel used after wards is for maintaining them in a usable condition.

OK proven system for fuel. Check the ingredients for any 'injector cleaner' and it will be mostly Liquid Hydrocarbon or Hydrocarbon Liquid. they are the same thing. go to a hardware store and you'll find it's Mineral Turpentine. Plain old turps is the magic injector cleaner! Now you can buy a brand name bottle with 300ml for $15 or 1 litre of Woolie turps or from Bunnings for about $5 and you get more than 3 times as much. Want a bit more kick with that? Put in the Turps AND a 1 litre bottle of Kerosene! Just use regular 91 ron fuel and add the two extras to a full tank and witness the difference. You're engine will be more responsive and rev quicker through the range than I guarantee it.I am chemical engineer.

Bit suss. If it worked, wouldn't everyone be doing it?

OK proven system for fuel. Check the ingredients for any 'injector cleaner' and it will be mostly Liquid Hydrocarbon or Hydrocarbon Liquid. they are the same thing. go to a hardware store and you'll find it's Mineral Turpentine. Plain old turps is the magic injector cleaner! Now you can buy a brand name bottle with 300ml for $15 or 1 litre of Woolie turps or from Bunnings for about $5 and you get more than 3 times as much. Want a bit more kick with that? Put in the Turps AND a 1 litre bottle of Kerosene! Just use regular 91 ron fuel and add the two extras to a full tank and witness the difference. You're engine will be more responsive and rev quicker through the range than I guarantee it.I am chemical engineer.

well, im from the older generation, and with all my carby cars i used to use a cup of turps a month in the tank to give the system a good clean, not sure if it really worked or not, but it is good for condensation in the petrol tank. i have run a car on 10 liters of kero once upon a time, but once again, that was an old carby car, those things didnt care what they ran on. cars like (WB statesmans, VC Valiants, VC commodores, HT holdens. ETC).

OK proven system for fuel. Check the ingredients for any 'injector cleaner' and it will be mostly Liquid Hydrocarbon or Hydrocarbon Liquid. they are the same thing. go to a hardware store and you'll find it's Mineral Turpentine. Plain old turps is the magic injector cleaner! Now you can buy a brand name bottle with 300ml for $15 or 1 litre of Woolie turps or from Bunnings for about $5 and you get more than 3 times as much. Want a bit more kick with that? Put in the Turps AND a 1 litre bottle of Kerosene! Just use regular 91 ron fuel and add the two extras to a full tank and witness the difference. You're engine will be more responsive and rev quicker through the range than I guarantee it.I am chemical engineer.

Here we go lol

Just like the recent threads on here of people discussing the use of E85 in their respective mitsubishis, it is worth pointing out that complex hydrocarbons such as turps will eat through all manner of rubber seals and fuel lines with extended periods of use in a car that isnt specced for it - especially in a 10-15 year old magna that was designed primarily with 91RON fuel in mind. Kerosene is about 1 poofteenth away from diesel, i cant see how either will raise the RON number any meaningful amount unless you are using very high concentrations - which is bad.

Toluene or xylene are far better additives to raise the RON of fuel and also as a gentle fuel system cleaner

your magna is designed to run on UNLEADED fuel, 91 min, e10 is acceptable.

Wasting money on 95 and 98 UNLESS you have had your ecu tuned to run it to stop advance timing pinging.

E85 will kill your magna or any other car unless its be designed or upgraded to run.


if you want more grunt then go root a pig, unless your can HAS BEEN modified to run those fuels your wasting $$$$

Good day.

My JDM Diamante has the knock sensor, and there is a noticible difference between 91 and 95. my wife put 91 in it when we first got it, and i was stumped why it was low on power, and pinged under load till i asked her. I know from the owners manual for my brothers KS V3000 (magna) that there was a 4kw difference between 95 and 91. why did they delete the knock sensor on 3rd gens???

My JDM Diamante has the knock sensor, and there is a noticible difference between 91 and 95. my wife put 91 in it when we first got it, and i was stumped why it was low on power, and pinged under load till i asked her. I know from the owners manual for my brothers KS V3000 (magna) that there was a 4kw difference between 95 and 91. why did they delete the knock sensor on 3rd gens???

Cost cutting, poor fuel quality

fair enough, NZ shit fuel quality killed the GDI engine over here

Took that into consideration and checked the fuel line from tank to engine and there is nothing that is lesser in quality than the PVC bottle that the Turps comes in. Simple Hydrocarbons bottles with a Wynns sticker = bigger profits for the manufacturer. It's exactly the same thing, just plain old turps. BTW, car running like a dream since using the turps to clean the injectors as they had done 105,000km. Turpls and 5000rpm changes and problem solved!

I changed from 95 to 98 soon after buying the VRX and noticed a difference. Perhaps not in a straight line drag but rolling start/acc when over taking, etc.

where did you get the fuel from I only ask that because my brother has a 95 magna, went through alot of difference brands of 98 fuel cause his car was running like a bag of shit, until he found BP Ultimite ran the car on that for about 18 mths, it was all for better fuel ecc and not performance.

where did you get the fuel from I only ask that because my brother has a 95 magna, went through alot of difference brands of 98 fuel cause his car was running like a bag of shit, until he found BP Ultimite ran the car on that for about 18 mths, it was all for better fuel ecc and not performance.

If his 95 magna was a V6 TS, these had knock sensors/RON plug (cant remember which) and actually prefer premium fuel

Just like to point out that the Falcon wants to murder me whenever i put 91/95 in it after having run 98 for a while.
Knocks it's ass off for a disturbing amount of time, before detuning itself making me lose ~10kw and .5L/100km.

Ah the joys of knock sensors. Atleast your falcon has one. Pity that Mitsubishi dropped this feature on the later TJ models when they were fitted to some of the earlier third gens :-S

Ah the joys of knock sensors. Atleast your falcon has one. Pity that Mitsubishi dropped this feature on the later TJ models when they were fitted to some of the earlier third gens :-S

No 3rd gen v6 has knock sensors, perhaps with the exception of the 2.4 4cyl but that was dropped from the TF range onwards

Thread cleaned up... this is a discussion about using different grades of fuel in a Magna... if you want to talk about engine conversions or exhaust upgrades, make a new thread for it...