What Petrol To Use?

[(OO)SKYLINE(OO)]

Here in the states, I use about 2/3 of a tank of 92 octane and a 1/3 of a tank of 110 octane...

Just for interest sake... What is the point of that?

Does that even / level out the RON?

[JSTA33]

ive seen the effects of using less octaned fuel..

ive ran 95 for a couple weeks and didnt notice much difference but decided to run 98 to be safe..

a friend on the other hand, used 91 in his sr20det and after a few weeks had big problems with lag, backfiring, and idling really rough..

why have a performance car if you dont want to look after it? its a price we gotta pay.

[mad082]

US octane ratings are calculated differently to here. 92 octane in the US is close to 96 octane here. generally you add 4 to the US octane and you are pretty close to the octane level of our fuel.

[kimbod]

Sorry Mad RON is RON in whatever country you are in. We used to test RON with a variable compression motor, now it is an IR reading and other hi tech stuff. Mixing 92 and 110 will give about a 100-101 RON so it's ok but levelride I though your fuel would have been cheap enough .

[central coast person]

You need to take the cheep fuel out of your tank to get your car going. Skylines cannot have this crap fuel in them unless all the seals in the fuel system have been changed too handle these types of fuel.

The fuel is simply 98octane if the car is set too run stock fuel. What has happened as when you were driving with the cheap fuel in there the seals in the fuel system have swolen up and restricted fuel flow. Thats why you slowly got power loss and when you came too idle the drop in fuel pressure was enough for the fuel supply too cut off and stall the car.

I have seen this exact problem you are describing many times with skylines and a 300zx so i can say go ahead too fix it

[joel_bruce]

Dude change your coil packs and injectors and run methanol

works out cheaper than pump fuel and has an octane number of 140

[KrazyKong]

Ok so being the noob I am, I've been running 91 octane (Shell or Caltex) for the past 9 months in my car. Idles fine, no misfiring etc. Isn't a rocket, but still felt ok to me performance wise. After being told a few days ago I should be running BP Ultimate 98, I've since done over 500kms with this fuel. Car certainly likes it alot better , and my gas mileage has gotten way better. Havn't noticed any black soot either on my exhaust. But then again I've only done 500km so far with this fuel.

Have I done any lasting damage to my car by running 91? I knew not to run that E10 rubbish, but figured the different octane levels were for performance only, and not the health and well being of the car.

[mad082]

Sorry Mad RON is RON in whatever country you are in. We used to test RON with a variable compression motor, now it is an IR reading and other hi tech stuff. Mixing 92 and 110 will give about a 100-101 RON so it's ok but levelride I though your fuel would have been cheap enough .

sorry mate but i never said RON did i? i said octane (not quite the same thing). and if you do a bit of research you will find that the US octane ratings ARE different to ours because we go off the RON rating and america goes off (RON + MON)/2. and since the MON rating is generally about 8 less than the RON rating (but not always), when you add the 2 together and then halve it it comes out about 4 less than the RON rating.

RON = Research Octane Number

MON = Motor Octane Number

as for fuel being cheap in america, that is somewhat true, but you also have to remember that the minimum wage there is about half of what it is here.

[mad082]

Ok so being the noob I am, I've been running 91 octane (Shell or Caltex) for the past 9 months in my car. Idles fine, no misfiring etc. Isn't a rocket, but still felt ok to me performance wise. After being told a few days ago I should be running BP Ultimate 98, I've since done over 500kms with this fuel. Car certainly likes it alot better , and my gas mileage has gotten way better. Havn't noticed any black soot either on my exhaust. But then again I've only done 500km so far with this fuel.

Have I done any lasting damage to my car by running 91? I knew not to run that E10 rubbish, but figured the different octane levels were for performance only, and not the health and well being of the car.

there isn't anything wrong with E10 fuels. i've been running it for a few years now, in various cars, as have others i know, without any troubles at all. generally people who have trouble with it aren't actually having trouble with the fuel but the cleaning properties that the fuel has and it breaks down a lot of the garbage in the fuel tank or the fuel filter and it gets deposited in the injectors. this is normally in cars where the fuel filter hasn't been replaced for a few years and is probably full of crap and not filtering very well anyway. very few people have had issues caused by the fuel itself.

as for performance of different fuels, there is actually very little difference in the actual fuel as far as how much performance it gives you. where the performance comes into it is from the octane rating, which is how hard it is to ignite. the higher the octane rating, the harder it is to ignite, so the more advanced timing you can run. on most modern cars the engine has knock sensors which register any pinging and then retard the timing to save the engine from damage. so if you run a car on the lower octane fuel that was designed for higher octane fuel on lower octane fuel then the ecu will retard the timing and you will have less power, meaning you have to use more accelerator (and therefore more fuel) to accelerate or even just cruise at a fixed speed. that is how you are able to get better fuel economy from higher octane fuels. but if you take a basic car that is designed to run on basic fuel you often won't see any gains from running higher octane fuels.

as for any damage you may have done, if the knock sensors aren't working properly, or the engine is still getting pinging once the ecu retards the timing then it can damage spark plugs or ringlands.

[kimbod]

We do actually use a RON and MON in Australia. It's just in the oil industry we use RON for simplicity. Before our 98 RON was released ,years of blending and dyno work was done to get the MON up to a high level. As you know MON is more of a driveabilty scale than RON. Research Octane Number is a comparison of the Platformate or Reformate [or what process is used in Catalytic Reforming to in crease the octane of the HSR ]to N-Heptene scale. The reformate or platformate leaves the units and goes to a Ben sat unit to remove the benzene down to levels mandated by govts. Heavy runs to tankage at around 102-105 RON and the lights go a reactor for conversion of the benzene. All these streams and other rundowns go to the blend tank for testing of RON and MON before release to the public. I can't go into specifics as the blending is proprietory knowledge. Obviously in Queensland all or nearly all your gaso comes from Caltex Lytton or BP Bulwar . A small amount may be imported .or in times of shortage or production problems from Caltex Kurnell or Shell Clyde. Though you may get some from India or SE Asia.

[mad082]

you are still ignoring the fact that US octane ratings will always be about 4 octane lower than here. it is common knowledge and has been for about the past god knows how many years. the fuel companies may still us MON when testing fuel, however when it comes to saying what octane their fuel is the simple say what RON it is. you may have a good knowledge of australian fuels, but you seem to have little knowledge about other countries octane ratings.

a prime example of this would be any cars shipped to th US designed to run on premium fuels would have dramatically lower power outputs if the US octane was actually only 92 RON for the premium fuel. the manufacturers would have to detune all the cars, and infact all cars, not just cars designed to run on premium would have to be detuned. yet they all seem to have the same power outputs and don't get detuned.

[kimbod]

I guess that as this started as an australian fuel thread , australian RON was main thread ,until level ride, came in with north american octane. since they use AKI as their basis of their octane figure . Still mixing the lower and the higher octane together you will get an improvement on the lower one. 50/50 would give a very close to mid range of the difference. Yes their ECU would be retuned for the differing fuel specs over here, though there isn't a great number of american cars coming this way compared to cars from SE Asia who use a rating the same of very close to ours. But back to australian octane per the thread, on our cars with closed loop systems with knock sensors you will get more power from the higher RON and noticable at that. so use the highest RON you can afford. Interestingly , the sales of 95 ron are up due to govt mandating E 10 with the phasing out of 91. I hope I have a passing knowledge of Australian fuels and manufacture as I have been making it for long enough.

[perzn_34]

hey guys so from this i read i have to use 98 octain? its like $1.50p/L .... isnt 95 good enuff?

[mad082]

depends on what mods you have. if your car is completely stock then you could get away with it, but 98 is the better option. if you are running higher boost or aftermarket ecu (that was tuned on 98) then you'll want to stick with 98. unfortunately that is just one of the many ways that owning a turbo import will empty your wallet.

[perzn_34]

i got like hks turbo .. just under a bar of boost stock fuel and ecu.... so u think 98? powa that on atm bov and daily driverr..

[mad082]

definately 98 for that setup

[iseekool]

All R34GTt should be running 98 fuel as a minimum due to the higher compression and boost, regardless if it's stock or not.

(I wouldn't know about older models)

[perzn_34]

i think i get wat u guys mean now... i draged my mates stock s2000 just now and he smashed me.. i was on 95octain.. moved to 98 now it feels alot bettter+

[LeCoq]

do we need to convert our fuel tank, fuel filter etc etc to put different kind of petrol in? or we can just pour it in right away no dramas?

[mad082]

if you are going from premium to regular or e10 (or the other way round) then nothing is needed to be changed. if you were going from unleaded to c16 or something like that then you may need to make some changes