I have read conflicting information on this topic online and on this forum. I am going to purchase a model S for myself soon and I haven't really thought much about this topic until recently coming across a thread on here that briefly talked about the 85 and 85D for highway driving. I will be driving 85-90% all highway commuting miles, so would a D version model be more advantageous than a non D for this type of use? Would I hold better rage through out my day with a D? I have read no, yes, and as much as up to 20% more effeciant for highway driving with a D model? Thoughts on this please.