G23 Owners?? That thread seemed like a bunch of G23 nuthuggers, and G23 haters, arguing about what the fuel mileage "could" be..... No factual statements
For what it is worth, the G23, that I spent time in, late this last summer, did not drink 19gph surfing with stock ballast + 3000lbs. We spent an entire afternoon surfing and wakeboarding behind it, and still had enough fuel to cruise around that night. It was probably more like 10-12gph.