The idea is to replace stock and 19T classes with mod and less cells. Replace 27T with 4 cell and 19T with 5 cell. That's a good idea, since a normal mod in a lower voltage will wear a lot less than a stock or 19T pushed to its limits. Testings have proved they are similar speed on the track so why not, as long as you can still do mod with 6 cells i'm allright with it.