14" to 15 " wheels

If you change your wheels from 14 to 15 will this alter anything like the speedo readings.

Dave

you need to basically work out the rolling circumference for the 14" wheel then when you go to 15's adjust the tyre profilel to suit. For exmample a 185 60 14, is roughly the same rolling circumference as a 195 50 15, so the speedo inaccuracy is minimal. The 60 profile  in 14" and the 15" in 50 profile have nearly the same rolling circumference in theory.
(Got how much of a nerd do I sound  8O  8O )

i got ya.

Worth comparing to a standard car at 70mph or so to find out the innaccuracy once the modification has taken place. Always best to do this because of all the speed cameras that are around.