Specs:
http://www.ltsa.govt.nz/publications/vi ... s-v2-3.pdf
Vehicle Inspection Requirements manual:
http://www.ltsa.govt.nz/publications/vi ... index.html
Has an FAQ on here thats useful
http://www.lvvta.org.nz/
you can fit any diameter wheel as long as the rolling circumference (the distance one turn of the wheel travels on the road) does not increase more than 5% over the original equipment without the need for an LVV cert. The main reason for this is that a substantially increased rolling circumference will make the speedo under-read (i.e. the speedo will read, say, 90kph when you are doing 110 kph).
Unfortunately what needs certifying isn't always in the WOF book.
The other thing to think about with ANY mods is that your insurance company may not cover you without a Cert.
Rolling Diameter aka Circumference = 3.14 x Diameter
Tyre Size = Circumference
28.9" (235/75R15) = 90.746"
31" = 97.34" == 7.27% Increase in rolling Diameter over 235/75R15
32" = 100.48"
33" = 103.62"
35" = 109.9"
I'm sure you can do the % thing
