Ok...

So basically...I understand that the higher the octane number, the more the fuel can be compressed before it spontaneously ignites from the increase in temperature that accompanies compression. I'm with you so far! I also realize that chipping a turbo engine works by increasing the boost pressure in the engine, so obviously, octane matters a lot on a turbo car, and even more after you chip it.

But my question is with the 2.0T and octane. Here in Taiwan, Octane numbers are 92 for cheap gas, 95 for regular, and 98 for premium. Audi recommends using premium. Ok I get it.

BUT...as far as I can tell from reading the boards....92 octane is already pretty high in the US...and I believe that in Canada the highest one can find is 94 at Sunoco. So....after I chip my 2.0T do I still need to add 98? I will...just because that's how I am...but I'm wondering...is the octane number really dependent on local conditions? So for example, here in hot and humid Taiwan, would 98 octane perform similarly to 94 in a cooler less humid climate?

Would my car really be fine on 92? (assuming that would be the premium gas I would be adding to the car if I lived in the US) Or is it localized?

 

Not sure how octane works in Taiwan but that’s pretty interesting. I know the highest at normal gas stations here is 91 and that’s what you’re supposed to put in your A3. The chip doesn't effect what gas you should put into your car unless your cars programmed with a new chip to take a higher octane. But id think 92 would be fine but that’s weird 92 is considered cheap gas there. Just out of curiosity, how much is premium gas in Taiwan per gallon?

 

Don't know how it is there, but US stations use the (RON+MON)/2, or PON, rating for octane. European stations commonly use just the RON (which is typically higher since it's based on testing at slower speeds).

For example, a particular gasoline may score 87 MON and 95 RON. In Europe, this gas would be a "95" at the pump, while in the US, it is "91".

Hope this helps...

 

Octane is actually the knock-resistance of the fuel. With a higher octane fuel, the engine can be run with more ignition advance, which generally allows for more power output.

Engines in different countries are sold with appropriate engine maps to suit the fuelgrade and quality and also the climate. So Audi's recommendation for premium fuel in your country means you should use the premium 98. If you use lower grade fuel, the engine will retard the ignition in response to knock andthis will result in lower performance and fuel economy.

 

Thanks everyone!

I think the different rating system explains a lot!

My TT will be sure to drink 98....

Fusion..not sure what premium costs here yet...my A3 was TDI...which was about $4 a gallon for the past 6 months. I'll let you know when I fill up my car after I take delivery tomorrow.