Own a 1.2 8V
but am running on 17" rims, lowered on coilovers and have fitted a 6 speed gearbox out a sporting...

Someone said my speedo will be out? Is this right??
Thanks!

yes it will be out but not by much lol

yes it could be out depending on tyre size etc

you can check it against a sat nav

the 6 speed gearbox wont change owt as long as the 6speed sensor was used IIRC

It'll be the wheels that'll be flawing the Reading

With a Sat nav / Interactive speed signs, see how much Roughly your out by
its only a rough Guide tho

ziggy

Fitting an incorrect tyre can result in your speedo being out quite a bit. A set of tyres I had fitted, resulted in my speedo being out by 15%!
Best advice I can give, is to read below and then make your choice.

http://www.miata.net/garage/tirecalc.html
http://www.kouki.co.uk/utilities/visual-tyre-size-calculator
http://www.carbibles.com/tyre_bible_pg4.html (fantastic guide)

Depending on the width, 17s will need something like a 35 ratio tyre. A sat nav can give a fairly accurate idea of actual speed.