Break point change could be due to more volume of oil. This usually results in a more direct line to the pocket. If you are judging your speed by the lane speed guns then that is probably the difference. I don't throw my spare ball any faster than my strike ball, but the speed gun registers a 1 to 1.5 mph faster speed.
It could also be the speed gun on your pair, or maybe your timing is better and you are just naturally generating more speed.
A lot of variables to guess.