preference on type of gas?

[DarkStar]

I was wondering what type of gas I should be using on my 240...I've been using mid-grade (octane rating 89+). Give me some feedback on which is best (performance-wise).

[ride4lame]

uh...premium...

are you kidding?

[quiksilvia]

ha ha ha, highest is best, cleaner-burns better. is that seriously what u were asking?

[Nathan]

My friend only runs 87 in his altima (KA powered too) and hasn't had a single problem yet...he's more of a cheapskate than I am!

[quiksilvia]

it mainly makes dirtier exhaust, but that leaves deposits in the piping and cat etc... over time not good. i noticed that when i run low gas, i could hear the valve tap get worse.

[dareo]

85 octane baby, runs the same as the 91 and 20 cents less. KA24E doesnt have a knock sensor either. Good thing it doesnt knock with 85 octane, it must be my old low compression motor balancing things out.

[methodchris]

85? lowest around here is 87

[DarkStar]

I'm pretty sure we have 83 around here somewhere...I know I've seen it.

[jdmfreak]

Damn 83 is mad low

[stealthj]

yeah, 83 IS mad low

i only use 89+ from 76 because they do not use MTBE in their gasolines

[uisce]

higher octane gas WILL NOT give you any better performance. If you have no knock/pinging at 87 octane, use it. Its cheaper and just as effective. I kid you not, there is no reason to run a higher octane gas in a naturally aspirated car (unless you are running some rediculous compression).

Turbo engines are a different story.

[quiksilvia]

at first i read that and was gonna kill uisce, but then he said turbo is different. i noticed that my ka and my bimmer ran better with higher octanes, no better performance...i dont know about that. prove it

[uisce]

at first i read that and was gonna kill uisce

how friendly of you.

lets get a few things straight. "Octane" is an 8-carbon hydrocarbon. Heptane is a 7-carbon hydrocarbon (see a pattern here?). Your fuel is primarily comprised of octane and heptane. Octane, unlike heptane, is very resistant to pressure-induced combustion, ergo the higher the octane rating, the more resistant your engine (fuel, really) is to "knock."

All this means is that your fuel is less likely to pre-ignite (combustion prior to spark ignition, often on the compression stroke and can lead to very fast and dramatic engine failure) and the "end gasses" (farthest from the source of ignition) are less likely to explode, causing "knock" or "pinging."

Contrary to popular belief, your air/fuel mix does not explode, but rather burns in the combustion chamber, ideally along a fairly uniform flame front originating at the spark plug. Also, your max cyl pressure is not at TDC, but rather somewhere near 90 degrees after TDC (which is when the unburnt air/fuel "end gasses" can become unstable and explode).

Octane levels are far more critical in forced induction and nitrous applications because of the extremely high cylinder pressures, and alcohol is often atomized and sprayed into the intake to both raise the octane level and provide a degree of "quench" to keep the combustion chamber temps at acceptable levels.

y'all tired of reading this yet? sorry for being preachy, but I dislike misinformation, had to throw in my $0.02

[quiksilvia]

I am friendly, its sarcasm. you have done a fine job at explaining what we are talking about, and u even said urself "can lead to very fast and dramatic engine failure) and the "end gasses" (farthest from the source of ignition) are less likely to explode, causing "knock" or "pinging." ", now if the fuel is exploding at the wrong time of the stroke, going against the rotation-slowing it down, is that less power? i think so

[Nismo_Freak]

higher octane gas WILL NOT give you any better performance. If you have no knock/pinging at 87 octane, use it. Its cheaper and just as effective. I kid you not, there is no reason to run a higher octane gas in a naturally aspirated car (unless you are running some rediculous compression).

Turbo engines are a different story.

You could effectively run 89 octane fuel in a WRX even with it's peak boost reaching 1 bar. Due to the active timing control.

Knocking and pinging are picked up by the KA24DE's knock sensor WELL before they are audible. In fact the ECU has a built in timing retard when knock values reach a certain point.

You can run 87 octane fuel, however the engine is designed (for DE engines) to run on 91 octane. However, knowing that most owners would put 87 in the car the engine is equiped with a knock sensor to prevent knock. A difference of 4 degrees of timing might not be felt on an engine by most people, especially if they are used to running 87 octane. Often the conditions needed to sufficiently create knock in the KA (dry, hot days) are often what get blaimed for ill-performance.

There is a reason the nissan engineers chose 91 octane for the KA24DE and believe me it's easily backed up by the fact that they would not want to put premium gas as recommended fuel due to the consumer wanting to run the cheapest gas available.

[droptopsilvia]

damn...got 87, 89, 91, 93, 94 around here. one place has 103 but thats a drive... I usually run the 91 or 93(it goes on sale for the price of 91 every once in a while)

[Checkered-Member]

I use 87 on my KA, there is absolutely no need to run higherWhen I get higher comp, I’ll go to 91+

For my Audi premium all the way…

[quiksilvia]

94.........hmmmmm. i think ill start running some alcohol

[Big Manne]

i never go below 89, try to use 93 as much *** possible and yes i am n/a. there is a service staion near me that sells 114 octane. all my forced induction friends love that place

[fiznat]

I usually run 89 on my NA S13.. I know I could probably get away with 87 but there's just something in me that says I shouldnt go cheap on my baby. I'll try 87 someday though.

Do you guys think 91 is good for a turbo-ed KA at about 9psi?

[quiksilvia]

highest pump gas is ok, i run 91 in my sr, but i know some peeps who run half 93 and half 103 in thier z32's, hella $$$

[DarkStar]

Alright, finally found a place with cheap 93. (Which is surprising because I never thought it would be as cheap as the 87 thats right around the corner). I'm probably gonna stick with that. Thanks for all the feedback/info.

[89240sx]

The book says 87 octane or higher... so I use 87 =)

and my KA and my wallet stay happy

[DarkStar]

Prices are about $1.40 to $160 depending on where you are

[240SX=fun4me!]

I pay 1.60 fo premium, and it says in the manual I have fo me s-13 KA24de, that i shud run premium, so I figure I have the money, why not buy prem. anyway? It burns cleaner? either way, Ive got new plugs in my car(Bosch +4's baby), so Im keeping em as clean as possible

[Toad[^_^]]

I was wondering what type of gas I should be using on my 240...I've been using mid-grade (octane rating 89+). Give me some feedback on which is best (performance-wise).

GOD! I feel ill:puke

[groundhogday1976]

I use 93. It's only an extra $3 per tank over 87, plus my owner's manual recommends at least 91. By the way, there IS NO OCTANE IN PUMP GAS! Octane rating is the percentage of isooctane blended with heptane required to match the knocking characteristics of the gas being tested. In other words, 87 pump gas has the knocking characteristics of an 87% octane solution.

[Toad[^_^]]

I use 93. It's only an extra $3 per tank over 87, plus my owner's manual recommends at least 91. By the way, there IS NO OCTANE IN PUMP GAS! Octane rating is the percentage of isooctane blended with heptane required to match the knocking characteristics of the gas being tested. In other words, 87 pump gas has the knocking characteristics of an 87% octane solution.

Good man. Thank you for that. And remember people, use fuel injector cleaner at every oil change. It keeps your engine happy (o^_^o)

[Nismo_Freak]

Good man. Thank you for that. And remember people, use fuel injector cleaner at every oil change. It keeps your engine happy (o^_^o)

Nissan posted a technical bulletin against using fuel injector cleaner.

[Toad[^_^]]

Nissan posted a technical bulletin against using fuel injector cleaner.

NOOOOOOOOOOOOOOOOOOO!Lies and deciet I tell you!(really? I guess I'd better stop then...)