would 1-2mm bigger in swaybar actually make a difference in handling?

 

1-2 mm is a sizable increase in bar stiffness depending on what size you are starting at.
going from a 15mm to a 17mm is an ~65% stiffer bar, and going from a 28mm to a 30mm bar is an ~32% increase in stiffness. taken from here

whether that will transfer perceptibly on the road or track is beyond my experience. ive made far more drastic jumps than 2mm. i went from on rear bar to a 13mm ls bar to a 21mm blox. the difference between each of those was huge, but i cant say whether or not i would notice 2mm.
but then again my car was pretty much excusively street

 

good info...i have a 94 civic ex rear sway bar (12.9-13mm) and want to get a gsr rear (14mm).

 

how relieble are the oem sway bars.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by saver &raquo;</TD></TR><TR><TD CLASS="quote">how relieble are the oem sway bars. </TD></TR></TABLE>

OEM usually means pretty damn reliable....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EK4civichatch &raquo;</TD></TR><TR><TD CLASS="quote">

OEM usually means pretty damn reliable....</TD></TR></TABLE>
would you be needing a stronger sub brace for it?

 

so would 1mm make a differents in handling?

 

OEM means like factory made. If you want "oem" you want FACTORY parts. There is a difference. There can be like an OEM spec water pump made for your civic but, it may not be factory.

Yes any marginal size difference is significant.

 

so i take it that you wont need any sub brace. or would it depend on wat car you have.