Lol,I dont have a wildtrak but I know driving anything over 65 blows up the fuel mileage bad. Have not found that eco vs sport vs normal changes much. But a heavy foot will. Also found I do not enjoy driving my Bronco trying to get 18 mpg vs 15 mpg. Either sucks, and I knew that buying this...
Hold off and live with it for a bit. Your mind may change on what you want to do. Do it once not twice. I never thought of doing a lift when I first got mine. Now I have a 4 inch lift because I changed my mind after living with it for 6 months.