Re: 5ktq Fuel Economy

["Wm. Josiah Erikson" <werikson@hampshire.edu>]

Nope : )
Higher octane gas has LESS power per gallon. It just burns slower, so you
don't get the preignition knock (well, I guess I should say that it is less
suceptible to spontaneous ignition under pressure). If your knock sensor is
constantly backing off the ignition timing because you're running too low
octane, I guess I could see that you might get better gas mileage by running
higher octane. In my Rabbit, for example, which has a 10.5:1 motor in it, I
get better gas mileage and more power out of 91 than 87 (in fact, it really
doesn't like to run on 87- complains a lot. I have no knock sensor on it).
But in my QSW, I get better gas mileage from 87 (8.5:1 JT motor)
    HTH!
    -Josiah

Todd Phenneger wrote:

> >You want to trade?
> >I get 13-14MPG in the city and 24-26MPG on the Highway (of course I have
> >a
> >K24 and 2Bar boost).
> >If you want to improve your MPG, use 87 octane, should give you 1-1.5MPG
> >more (maybe).
> >Avi
>
>         Uhh, How do you figure.  Higher Octane allows the motor to run
> better so you should see better Fuel Economy with the 93 octane.  I do on
> my car by a 1-2 mpg.  With Higher Octane you get more power per gallon so
> you use less gas.
>         Right???
>
>         Todd Phenneger
>         1984 4000s quattro / modified/ awaiting Turbo Transplant.
>         1985 4000 quattro / Silver / Fixing it Up.
>         1987 4000cs quattro / Saphire Metallic Blue/ Girlfriend's
>         1996 A6q / Volcano / Dads Car
>    *****1985 5kt / PARTING OUT!