Can't speak to the GXP ghost, but my N/A ran 28-30 mpg on last summer's road trip, a mix of A/C on and off. (Same 1 mpg variance between on and off.)
The A/C compressor is a parasitic load, but it sounds like yours is a bigger parasite than most. Going bad perhaps? I don't know if there is a "torque" rating for how freely it should spin when engaged.
The A/C compressor is a parasitic load, but it sounds like yours is a bigger parasite than most. Going bad perhaps? I don't know if there is a "torque" rating for how freely it should spin when engaged.
