MGM vs MMM speed runs????

[mkrusedc]

Click on my sig for the truck's build thread.

weight 10.5 pounds
Neu 1515 1y
two 2s1p Trakpower lipo
3906 single speed conversion
Revo Talons
1/8 scale buggy diffs
51/20 gearing

MGM Highest speed 33.2 mph
setting:
Car mode <->
light brake
auto timing
reduce rpm
4s li-xx
free wheel
no brake at neutral
no auto correction

MMM higest speed 42.1 mph
setting:
Brake/reverse proportional w/ reverse
Brake 50%
Reverse throttle 40%
Punch 0%
Drag brake 10%
Start power high
Motor timing 10
Throttle curve linear

How can this be? I know my drive shafts rub against my lower spring retaining cups and the tests were do weeks apart. Would less friciton account for almost 10 mph difference?