Volkswagen Repair: Gti VR6, fuel mileage, grade fuel

Question
Does one necessarily have to use the highest octane gas for the gti VR6?  Or can you get by with the lowest?

Answer
Hi there Nim;

The VR6 GTI is my personal 2nd favorite Volkswagen.  They really should have the best grade of gas available, but in a pinch if you use the mid-grade fuel they will be just fine.  The reason you don't want to use the lowest grade of fuel is because it will create pining, or detonation in the cylinders, and start to crack, and maybe even break the ring lands, on top of the pistons.  But, if you use the midgrade gas the computer for the engine can normally adjust timing to compensate.  Your fuel mileage will go down, but not a lot.  Hope this helps, Nim, enjoy your GTI!