by "force 4g" im guessing you want to only have the lte radio on not the cdma/lte radio that is accessed. The answer is no. there is no switch that i know of that is built in to the phones UI. Im sure that there may be an app for it or some for of root but not fresh out of the box can you force 4g. and it does depend on where your location is and if you get a strong signal or not. Its going to be a battery vacuum either way but the stronger the signal, the better chance of it using 4g more predominantly anyway. Im in Wilmington DE and the signal is very strong so i use the 4g often. If any of this helps...