i recently upgraded to 16 inch rims on my civic and i am using 205/50/16 rubbers..
from an online gear calculator i can see that my actual speed at whatever rpm in each gear has increased..
so it would be safe to assume that now when my speedo says im going 125km/h @ 4000rpm in 5th gear, i am probably going a few km/h faster (130-135??)...
how do i go about correcting the improper speed being displayed?
what is the process in recalibration?

 

Your speedo is only going to be off a little. Maybe two to three MPH's. Most cars speedos are off by two to three. So don't worry about it.

To fix it you need to re-gear your tranny gear that is associated with the speedo.

You might be really close to the actual speed being that my speedo is fast by two MPH's

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 187Chor &raquo;</TD></TR><TR><TD CLASS="quote">how do i go about correcting the improper speed being displayed?</TD></TR></TABLE>

The best way would be to mount proper sized tires. Not only are you altering your speedometer and odometer readings, but your effective overall gearing is also being changed.