[sciphi]

If it's Savannah, GA, I'd absolutely run premium year-round. The heat and humidity do a number to a car's throttle response down there. Running the air conditioning at setting 2 or 3 for 9-10 months of the year definitely won't help, either.

I'd get the re-flash at the dealer for the hesitation, re-gap the plugs, and run premium in the tank going forward. Also, look into a tune if the hesitation is still there.

 

[sciphi]

Agreed, these turbo engines respond differently than a NA engine. Even at high RPM's it's shift, wait a hair, and then go. Definitely needs some planning instead of instantly going.

Throttle response on some GM engines isn't all it could be from the factory. Even my old 3800 Series II (L36) Buick had an awful lag before it would kick down and go. A tune took care of that, and made the car drive "like it should". Nothing like mashing the gas at 35 mph, as it would do a 3-1 downshift and rocket forward.