6s packs last longer than 4s?

[Finnster]

In addition... there is simply more total energy in the larger pack. Makes sense right as its bigger and heavier? ;) if you are pulling the same power from the pack, the one with more energy will last longer ( as briang said)

Energy= voltage*capacity (ie mah) or power*time
EG E=22.2V*5Ah= 111 Watthours (vs 14.8V*5Ah)

So to my understanding, you multiply the voltage by amp hours to get watthours and the higher the watt hours, the longer the runtime. Correct? Does this still workout the same if u run 4s with a 2700kv and the 6s with a 2000kv motor as long as u gear them for the same speed?