HEY PPL,


JUST WONDERING,

CAN ANYONE TELL THE DIFFERENCE BETWEEN THE GAS OCTANES( 87, 89, 91 AND 93)? MY MANUAL SAID TO USES 87 BUT FOR BETTER PROFORMANCE USES 91. RIGHT NOW, I'M USING 93....THAT S H I T GOES DOWN LIKE WATER....I'M THINKING ABOUT USING 89. WHAT DO U GUYS THINK???

 

I'm thinking...

CLICKY

Anything over regular octane in a non SC engine is a waste of money IMO as there is no need for it.

 

I have read there is no noticeably or beneficial difference in a non SC engine. I run the cheapest stuff, 85.5 here in the mountains...

 

In some cases, the carbon build-up inside an older engine can cause higher compression, thus necessitating the need for higher octane - or more importantly a method of "cleaning" it off.

A general rule of thumb is to follow what the manufacturer recommends unless you have a mod that creates the need. Otherwise you are just dumping extra money down the toilet.

 

You might want to hit the button to the left of your "A" key, by the way.

 

thx for the feedback...

 

What do you drive?

 

i always get better gas milege(at least 30miles per tank) with 92Oct ???

 

I HAD A 91 LEGEND COUPE....SOLD LAST YEAR AND BOUGHT A 03 4RUNNER SR5 V6.


OLD CAR.....



NEW CAR

 

I use 91 here in Cali. I'm 300 feet. Depending on your elevation, try different octanes and see what it does for you. In theory the higher altitude the less octane value you need.

In theory with modern engines like yours the engine managemnt will adjust to provide the optimum performance for the conditions. SO it will adnace timing till it senses pinging and start retarding it, etc. This means with higher octane it should push for a bit better engine performance which normally means better mileage. However there are a number of people that do not notice the difference.

I run on 91 and get pretty good mileage if I look on the forums, maybe it is just driving style. But I get 15-16 in town and 20-22 on the highway normally. I typically drive fast 80mph on the highway and go faster than traffic in town, but I dont drag race, etc.

Try a couple of tanks of 87, 89, 91 and 93 and see what works for you. For me it makes a difference for other people it doesn't. Your engine will be fine down to 87, as it will retard timing if it needs to.

Dont expect car mileage with a SUV.

 

A little off topic, but here in Wyoming (where I'm visiting) the low grade gas is only 85 octane. Whats with that? I was hesitant at first, but at $1.68/gallon I couldn't afford NOT to get it!! NO problems yet.

 

Gapguy-

Is the town you bought the fuel in at a higher altitude?

 

This town is at about 4400'... all through WY, the gas is the same octane. 85, 87, 89, 91.. Yes, all 4 at one pump.

I see these low octanes all over the southwest, but NEVER have I seen it in CA. Seems to run fine for me.

 

I have never seen 85 in Phoenix...only in Flagstaff. Weird.

 

The altitude is the key to the octane ratings: the higher you go the less octane you need for detonation due to the thinner air. Here in CO, we sell 85, 87 & 91 unless you're in the southwest corner of the state (Durango, Cortez, etc.) where they sell 86, 88, 91 as they do in most of AZ & NM. The lower octane prevents knocking, pinging, and carbon build-up while still maintaining the same combustion characteristics.

One question I do have is about ethanol. Supposedly it has a higher octane rating than "pure" gasoline and helps raise octane levels when mixed with gas like many states do. Would that make it safer to run with a SC in a pinch if premium gas wasn't available?

 

also a lower octane will burn faster but not cleaner, to combat this problem evrey two tanks i add one pint of STP or if it is cheaper A.T.F. lot of cleaning power in A.T.F.

 

ATF? In your gas??! Please tell me you aren't putting Automatic Transmission Fluid in your gas tank!

I'm hoping ATF is a fuel treatment.

 

a small amount of ATF every other tank or so wont hurt, its basically the same as some fuel treatments

 

Yikes! News to me!

 

no atf is transmission fluid there are so many detergants in atf it will clean almost anything you dont have to try it but works very well learned it from a old timer