People claim the EREV i3 won't do extended highway but I did Boston MA to Wichita KS in one shot in my 2014 with a hurt battery using Hold State Of Charge mode starting at a 75% battery charge and using a 7 gallon fuel cell in the frunk with a transfer pump to allow longer stretches between refueling. It worked a treat. I have since removed the additional fuel system once I got to Wichita and now it is my daily commuter and goes 2000+ miles between fillups.