I'm cautiously optimistic about the range increase, that being said he went from a sticky PS4S tire to an all season tire, rolling resistance is definitely going to be reduced. Also I don't know exactly which tire he got but the tread width on a 235x45 is likely narrower than the fat width of the stock ps4s, which would also contribute to rolling resistance. I'm hoping for some range increase in going to 18 but I'm doubtful that I'll get 10-15% if I stick with ps4s and have a similar tread width. Once I get mine I'll post any range findings.