Does the owners manual call for?

I know most will say to use premium but what does the owners manual say?

 

91 OCT as a minimum, in case of a emergency where premium is not available, regular can be used for a short spand of time as long as the car isnt driven hard, in addition it also stats to use as little as the regular as possbile and refuel with premium as soon as possible.

 

91 is minimum as stated, it's a high compression engine, lesser fuel will likely pre-detonate. I use 94 Of corse today being 1.40/L it's getting a little painful.

 

I use 85 octane, no problems here!

 

when you open the gas compartment lid it says right there to use premium octance gas only (minimum 91 octane). Gas is expensive, but the difference between 85 and 91/93 for a full tank is only like 4 bucks (but you'll never actually fill 20 gallons so less than that). If you fill up once every two weeks, and the difference is $0.20 a gallon, you're talking about $100/year. Might as well spend the extra $100 to make sure your car doesn't need extra repairs in the future, which would definitely be more than $100.

 

From the Owner's Manual:
FUEL RECOMMENDATION

Use unleaded premium gasoline with an octane rating of at least 91 AKI (Anti-Knock Index) number (Research octane number 96).




If premium gasoline is not available, unleaded regular gasoline with an octane rating of 87 AKI number (Research octane number 91) may be temporarily used, but only under the following precautions:

CAUTION

Using a fuel other than that specified could adversely affect the emission control devices and systems, and could also affect the warranty coverage.

Under no circumstances should a leaded gasoline be used, since this will damage the three-way catalyst.

 

oops...sorry for all the space and font glitches...I copied and pasted from a .pdf document. <G>

 

Somebody uses 85 octane? you're nuts. I use 93 octane.

 

I wish i filled up once every two weeks. But at 2.5 times per week you definatly feel the impact in your allready empty wallet.

 

damn well you're doing a lot more driving than i am i guess. but if you think about it, that's still "just" $300. To avoid possible problems, it seems not worth it to not use premium, at least imo.

 

Actually, we'd probably get less mileage with regular fuel. We'd have to refill more often and end up paying more money...

I won't try it with my Z, but with my Impreza RS (2.5l N/A), it's cheaper to run premium than regular...

 

OK, what if I can't get 93? Can I use octane booster (STP etc.) in emergency???

 

85 octane? And this is why I refuse to buy a used car. The car is tuned for the longer burn of the higher octane gas. Using less is asking for eventual engine disaster.

In general, if anyone can't afford the difference between a tank of regular and premium, they bought the wrong car.

 

Do you have an owners manual? Is not download one.

 

I have never seen 85oct gas....where the hell do you find that? lol

 

Sure !

 

So what are you guys opinon on Octane boosters? Not for everyday use but once in a while, like for going to the track?

 

High altitude areas. Here in Salt Lake City we have 85, 88 and 91. Technically since the air is thinner (we are 4800' + above sea level) you can get away with using slightly less octane as the burn is different up here.

 

But doesn't the ECU correct for the air being thinner, as in, shouldnt the ECU lean out the fuel to compensate??

 

Actually, Camel is nearly correct. Higher altitudes/thinner air lower the fuel's knock point. The 91 octane works exactly the same here in Denver as 93 does in Atlanta, hence for us, 91 is premium grade. From what I remember of what I once read on Chevron's web site, gas is octane-rated using the same formula at all elevations. The variables of course change to render different octane levels at different elevations. The gas itself is the same.

EDIT: I found the following article afterwards. http://www.imoc.co.uk/technical/article/octane.htm#q31
You will look towards the bottom 1/3 at the question "What is the effect of altitude". BTW, this article will tell you more about octane ratings than you should really ever know!