old thread, i know, but rather than risk a "use the search button" warning, i'll just add on here.
I had a GPS and a friend in my car (borrowed both, i have no friends).
He was watching the GPS screen for speed readout. Apparently, this unit updates 5 times per second, so i assume it's accurate.
At 60kph on speedo, the GPS stated 65kph.
At 110kph on speedo, the GPS stated 112kph.
This sounds backwards, does it not?
I have 18's on my car. And i assumed my speedo would be out a little.
But it looks to me as if the speedo/needle isnt really accurate, or the error/difference would have increased at higher speeds.
How have you guys found your R33 speedos to be?