13.5 3.7v does the same laptimes as 13.5 4 cell. So no it is not equal to 17.5 4 cell.... The bigger part of the picture is the corner speed vrs straight speed. Laptimes for 3.7v with the 10% drop in wt gain all the hp loss back in corner speed and run the same laptimes but in a rd course environent it makes for a messy race as if you have similar skilled drivers the flow lines are different through corners and into the straights.