Is there a performance gain with 4mm hose?
 

Hi,
I have a CAT 339DL excavator and it currently uses the 3mm hose and fittings throughout.
I have seen a diagram in my internet travels that showed 4mm hose going from the pump to the valve block then 3mm hose to the rams, and 4mm return hose from valve block to tank.

Is it worth changing out the main feed lines to 4mm, is there any improvement when moving 2 rams at the same time?