what is your mpg?

[ThatVietGuy]

In my general area, 91 will generally run somewhere between $2.60 and $2.69

[Monkeyman]

The octane rating refers to the amount of cyclic octane molecules in the fuel. Translation: Higher number = more ring type octane molecules. Octane is an 8 carbon molecule, and it can be in a straight chain or in a ring so that every carbon is connected to two other carbons. Regular straight chain octane is as weak as any other straight chain molecule, but cyclic octane is far stronger under compression. If your engine is running high compression in the combustion chamber then you need a larger percentage of your fuel to be made up of cyclic octane to handle that compression. Most of these Solara engines have low compression numbers, so they can run 87. If you are running the TRD charger, a turbo, or you have had your head decks milled, then you should move up to a higher octane fuel to prevent "pinging," knocks, and possibly detonation. To the point: You won't see any benifit to a much higher octane fuel if you are running low compression numbers (ie 9.5:1).

By the way, I am a chemisrty student at UMass so this isn't a load of cr*p!

Hope this helps,
David

[Mandarinsolara]

location: central florida
Year: 2000
v6/I4: 3.0L V6
Auto/Manual transmission: auto (i drive it manual style, a lot)
Mileage of your car: 57000
Tire size: i dunno, stock 16" rims tho
Force induction: n/a
Intake Mod: swiss cheesed lower intake box
Exhaust Mod: stock
Octane used: premium usually
spark plug used: oem
engine oil used: oem
average miles per gallon: anywhere from 8-20 in the city, and i logged a little over 32 on highway
freeway/local driving %: 5%/95%

[dominoSLEV6]

To the point: You won't see any benifit to a much higher octane fuel if you are running low compression numbers (ie 9.5:1).

Maybe I'm goign to sound stupid, but I was under the impression the gen 1 V6 (my car) has a compression ratio of 10.5:1. I never checked in the manual or anything, but anything I ever read online said that. Wouldn't that in turn make a difference in using 93 octane as compared to 87 octane?

And thanks for the information, it's nice to know how that all works from someone who knows what they're tlaking about.

Oh and also that sucks about Cali gas prices. Here the cheapest 93 octane is the Citgo up the street at 2.35 per gallon. However I use the Ammoco across the street from the Citgo which is 2.49 right now I think. They just put in these new kinds of pumps for the ultimate so you can see through part of it, and wow, Ultimate ACTUALLY IS clear. Almost as cool as shiny metal objects in my opinion.

-chris

[Turbosolara]

no one reads my post at general forum........
http://www.solaraguy.org/viewtopic.php?t=18596