Analysis of Power consumption with DatCon : strange results ?

[Atlantic Surfer]

Can't fly now (cracks, weather ..) so I try to analyse power consumption (watts) between a stock bird vs the same P3 with a battery mods, so loaded with about 400 g more.
Download DatCon to examine my flight logs ( nice tool Thanks BudWalker )
Results is not what I expected :
Stock P3 in long distance flight, way out at between 45km/h and 50 (28>31 mph/) and back at RTH
- Fly 1 : Total distance : 10300 meters / Watt max : 228 / Avg Watt : 154,5 / Max A : 15
- Fly 2 : TD : 12460 meters / Watt max : 280 / Avg Watt : 153,4 / Max A : 19,7

Battery mods
- Fly 1: way out at between 45km/h and 50 (28>31 mph/) and back at RTH
TD : 16Km / Max Watt : 1126 (!!) Avg Watt : 139 / Max A : 65,4
- Fly 2 : Way out between 30 and 35 Mph, back between 28 >32 Mph
TD : 18,2 km / Max watt: 1130 / Avg Watt : 109 / Max A :65

So how a P3 with 400 g more and more speed can drain 40% less than stock one ??
Is anybody have some numbers like that to share ?

And what is the max A of the ESC ? this 65 A (at take-off only ) is a bit scarring