i guess this is alittle bit off topic but ill ask it here anyway. when you first got the X was teh gas mileage worse than it is now?(if that makes any sense)
With 2700 miles on the odo, the mileage has remained unchanged, around 16 mpg. With 2700 miles on the odo, there better not be any gunk in the tank.
In this weather, You make the gunk, the less fuel in the tank, the more gunk you will be making. Ever gone to survival school? Know how to make water? Same principal. Seal your tank and let the temp change a few times, water in your tank. (Condensation) Mix that with all the varnish from the fuel = Gunk. The fuller the tank, the less the condensation and the formation of varnish form fuel.
I been to quite a few auto plants. Trust me, new don't mean anything there. Where do you think they piss when the Foreman won't let them stop the line? Not on the floor where they work.