Traction control has 0 effect on your fuel mileage. As noted, something else changed. Traction control is regulated by the government, so even if Ford had you design a car, it would still have to have a button that turns off traction control every time you start it, just like every other car for sale in the US right now. I really don't understand why you would want to shut it off every time, the only reason to shut it off is if you're stuck in snow or sand or if you just want to make some noise spinning your tires.