Hi There...Does the GTZ need premium fuel ?

Teh GTZ does not require Premium fuel, but it can't hurt (except in the wallet).

I would recommend using premium even though it's 20c more than regular. The engine is built to use premium gas and if you don't use it, mileage and power do suffer. The engine detects the lower octane level and adjusts, but not in a good way...

It's a pain and expensive, but in the end the car will like you better for feeding it premium.

Not to mention damage to internal parts like heads and injectors from prolonged use of incorrect fuel octane. Improper combustion, burnt rings, valves etc..