Efficiency?

[brijar]

My friend and I have similar trucks, but he always gets more runtime than me, even though I have much higher capacity batteries (mine are 5200mah, his are 3850mah, same voltage).

My truck:
Revo 3.3 converted to single speed with RRP steel trans gears geared 25/40
Castle/Neu 1518 1800KV
Castle MMM (older one with bullet plugs on the battery terminals, perhaps version 2 or 3)
6s Turnigy 5200mah 30C hardcase (three 2s packs in series)

His truck:
E-Maxx with newer chassis, but older 2 speed transmssion
Castle/Neu 1515 2200kv
Castle MMM (newer with battery wires soldered to the board, version 4 or 5)
6s Thunderpower 65c 3850mah (two 3s packs)

Could it just be driving style? He usually gets at least 5 to 10 more minutes than I do. My Turnigy packs are getting fairly puffy and I had to go to 5s because one cell was always lower than the others. My charger will usually put 4800mah to 5000mah into the packs after a run with the MMM set to 3.1v/cell. Thinking about changing it to 3.0v/cell.