I realize there's a thousand variables but when I switch to road tires from knobbies, how much more range can I expect, if any. I can go 40mi. now on a full charge. Going from cheap Kenda knobbies to Schwalbe MotoX tires is the plan. I'm hoping for a mile or two more range since the tires should have much lower rolling resistance. Has anyone actually compared their range when going from knobbies to street tires?