[DrJones]

Re: octane rating

Low octane gas in a high compression of forced induction motor can created a condition of early ignition called detontation. When the fuel-air mixture ignites before it's supposed to, the downforce placed on the piston before it completes it's upstroke can cause serious damage to the motor. While this condition is rare, it is a possibility. The motor in the GTI is designed to run best on 91 octane gas.

 

[DrJones]

Re: Octane Mixture

The octane rating in gasoline refers to the amout of the straight chain hydrocarbon octane (C8H18) in the gasoline. The more octane in the gasoline, the more thorough the combustion. Octane also adds stability, making it able to take more compression without the risk of detonation.

The reason it says 91 minimum is because different parts of the country have different octane levels. Where on the east coast mid-grade might be 89, on the west coast, mid-grade might be 91. I've seen premium as both 93 and 95 before. It all depends on the refinery the gasoline comes from.

Edit: To answer your question, the only things you'd accomplish by mixing is wasting your time and making two transactions at the pump for one tank of gas...

 

[DrJones]

Re: Octane Mixture

...but I'd love to see the faces of onlookers as you put one pump in, took it out, and put another pump in.

...And you shake it all about.

Or would so try to stick both in there at once, like a porno?

It'd be even better if he pulled the nozzle out and sprayed it all over the hood when he was done.

 

[DrJones]

Re: Octane Mixture

With a handle like rodknock, I figured you'd be an expert on octane ratings.

 

[DrJones]

Re: Too high of octane??

There are two different ratings for measuring octane. RON and PON. The RON (Research Octane Number) is used throughout Europe and ends up being 4-6 points higher than the PON that we use here. The PON (Pump Octane Number), or (R+M)/2 method, is what's used in America.

 

[DrJones]

Re: Too high of octane??

yes in spain we use litres, what is the equivalent of a gallon in litres??? I use to hear that fuel was much cheaper in usa than in europe.... nevertheless the fuel price in spain is one of the cheapes of all europe.

1 US gallon = 3.8 litres.