Re: Octane question.

[SCIROCCO2@t-online.de (Dirk Schneider)]

Josiah is right here,

it is a common fault that people think
hi-octane fuel has more energy
than lower octane fuel.
In fact that is not true, it has even a bit
less kJ/kg ( energy/mass) than low octane fuel.

The increase of power that a motor can have from
high octane fuel is the fact that the timing can be preset
some degrees which provides more power but also higher pressure
and so you need high octane fuel for that to avoid pinging.

The more you retard timing the less  power you have
but the lower octane fuel you can use.

Lauri, don't worry, it is not true that you can overheat your engine with
high-octane fuel. That's just a fairy-tale from people without knowledge.

Greets
Dirk


Subject: Re: Octane question.


> My car gets better gas mileage and has more power with 87 than with 94. 87
> octane burns faster and has more useable power per gallon than higher
> octane gas. The only reason to use higher octane gas is because it burns
> slower and is less susceptible to ignition under pressure, which is why
> you need to use it in a high compression motor. My car is an 8v, though -
> the 16v's are higher compression (10:1?), and if I had one I would use 89
> or 91. My '87 GLi (10:1 motor) liked 89 better than 87 - it would run fine
> on 87 because it had KS ignition, but it had more power with 89.
> -Josiah
>
> '84 GTi
> http://bork.hampshire.edu/josiah
>
> On Fri, 28 Jul 2000 BrianandDeborah@aol.com wrote:
>
> > There was a good article in European car some months ago about RON vs.
> > Octane.  Basiclly RON is a higher # than octane.  A friend explained it
to me
> > like this:  If you''ve got a scirocco it's a pretty good bet it isn't
new,
> > and gas has definately improved since say 1988.  He told me that using
super
> > was a waste of money.  As I'm writing this I'm remembering who told me
this.
> > He was a mechanic and a gas station owner, so he should want me to buy
super.
> >  I actualy alternate between 89 and Super and my car runs and sounds
great.
> >
> >
> > Brian
> >
> > 88Scirocco 16V



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