I've already seen several posts about this so here is a quick run down following a quick summary of what I'm about to say.

Higher octane gas will not help the Ralliart.

The octane number you see at the gas pump is a rating. It is an idication to the resistance to detonation. Cars engines that run high compression, high heat, advanced timings, high revs, ect. use higher octane gas. They are designed for it. The Ralliart is none of the affore mentioned things.

Unless you get some sort of engine management to advance timings, there is absolutely no benefit to running higher octane gas than 87. The only exception would be areas with crappy gas like California. In places like this 89 should suffice.

High octane gas is designed to resist higher heat and compression levels. Lower octane gas put in the same engine would detonate before the spark plug even fires. This is called knock. Knock can destroy your engine. This is why high octane gas exists.

Low octane gas is designed for everyone else. If you put high octane gas in a car without high heat or compression, it will not burn as clean. It will leave a residue on your exhaust valves. This will hamper performance.

In a nut shell: don't use high octane gas unless you have made a lot of modifications.

 

I usually try to run mid-grade gas myself...I found in my 88' Merkur that it ran better with it, and I would get slightly better gas mileage... it never had any mods the only non-stock peices were that the exhaust was slightly modifeid due to the fact that to replace teh stock peices would've cost $500 for just parts, and so instead when to a good shop in town and for $140 got a custom exhaust. Oh, and when I changed the plugs I switched to platinums...

so maybe that's why, but personally I just perfer the mid grade to low....wouldn't use hgh rade unless I was using a turbo or something.

 

I'm sorry but that makes no sense. 87 octane in cali would be the same as 87 elsewhere in the country. Crappy gas comes from "no name" gas stations that sell their gas for something like 30 cents cheaper then the major stations.

 

I gotta agree with that, I've noticed that my car runs much better on the same octane gas from Shell over Arco. I know gas is gas is gas but the formula is different from company to comapny.

Overall though 87 octane is best for a non turbo engine anyway. Besides if you read your book, it actually says to use 87. My thought is if after years of developement, if some scientist in Japan who wasted three years of his life, lost his wife to the neighbor and lost 45 pounds figuring out that the Ralliart runs better on 87, then by God, I'm goin to run my car on 87 octane.

 

California prohibits a certain fuel additive that most stations like to use. It is purely for emissions purposes. It makes the fuel more stable, and it is also cheaper to use than the California crap. California and Nevada are ghey like that.

In addition, if anyone has noticed, California only has 91 octane gas while most of the rest of America enjoys 93.

 

It is actually most of the west coast that only has 91. I have only seen 1-2 gas stations around here that carry higher than 91 and it is usually 92.

 

i thought the higher the octane to better performance the car is gonna do?

 

Higher octane = Higher Ignition Temperature...So if you have a high compression engine or forced induction (turbo, sc) and are getting pre-ignition(knock) higher octane will prevent this from happening.

 

When I run higher octaine in my 2003 OZ lancer I notice the cars faster, I also get better mileage. (especially if I'm running 94 techron)

 

^^^^ notice = think because higher octane can not give you higher gas mileage. It can only prevent predetonation, commonly called knock and/or ping. The only measurable thing you can notice from 93/94 octane vs. 87 is how much faster your wallet gets thin.

 

i been in 800000000 debates on this issue

i have PROOF on my old accord that putting in 92 octane gas, the ecu advances timing automatically and putting in cheap azz 87, it retarded timing

advance timing up to 42 degrees
retard timing up to -2 degrees

it's a noticable difference...

I just have to hook up my pocketlogger and show you it does the same thing on RA..

i just don't like rumors that get pass around as gospel

-joe

 

How about this.

Let the retards that want to waste their cash onhigh octane gas and think that their car's going faster (Kinda like decals add speed )

And everyone that actually knows what they are talking about use the gas that's affordable and meant for your car.

 

^^^^ I second his statement

 

lancerart:

i had datalog timing advances/retards on my car to see high octane makes a difference.. what have you done other than be an armchair mechanic?

i had dyno with different octane levels to see it makes a difference.. what have you done other than be a e-thug?

before you go call people retards, you should look at yourself to see if YOU are full of unsupported, unproven "facts"

and if any of you are in the toronto area, come by and i will show you the timing advances on YOUR car...

-joe

 

okay okay so you guy say 87 octane is better for the RA right doesn't the older the Gas the more bad stuff is gonna plug your fuel injectors? i heard the higher the gas the cleaner it is and you will run better?