I just bought a 2001 ming blue 2.7T Quattro i'll post pics once the camera is charged but i was wondering what kind of gas i should be puttin into the car

Thanx

is arguably harder on the motor.

I wouldn't do it personally, but you could probably get away with it.

i'll just play it safe and just use 91 octane

I did this test a few times with my 2.7T- 6 speed. I got 8% less MPG for 8% less cost 93 vs 87 so I didn't saving anything at all by going to lower octane.

The ECU adapts the engine to use the lower octane fuel without knocking/detonation.

1 lb of fuel contains about 18,000 BTU no matter if it's 10 octane or 100 octane. The main thing higher octane does is slow down the burn rate of the fuel/air mixture. This is needed at higher temperatures and pressures (hard acceleration) when the fuel/air mixture wants to explode rather than burn (a subtle difference). If it explodes you hear a knock.

All cars sold in the US are required by law to run at least on 89 octane. Your engine computer will sense knock and retard ignition timing which will reduce your max power potential.