[Rattler]

Hello All,

I was looking into the idea of getting mags (rims) to go on my i30 crdi, but my brother raised a valid point in regards to larger wheels and tyres throwing out the accuracy of the speedometer. The idea of having the speedo recalibrated or getting a reduction/calibration gear (if one even exists)(????) to ensure i don't end up with a slew of speeding tickets, makes the idea complicated and/or more trouble than its worth.

any and all help / input appreciated.

Many thanks,

                  Rattler

p.s. the picture is what the style of rims i was looking at.

[eyecon]

Man why didn't I think of that. doh! I think I'll delete my earlier post because it's so crappy anyway, and insert my new comment here instead. I don't think Rattler read it anyway. Sorry if you did mate 

[Dazzler]

Rattler,

Here is a tyre calculator link

http://www.miata.net/garage/tirecalc.html

This will help select a suitable equivilent .. also any tyre place worth their salt will help you choose the correct equiv (so it is not that hard after all)

and we have a resident Tyre expert at your disposal (who is currently travelling overseas) he is Trev (AKA Surferdude) and i'm sure he will respond to any questions you PM him (He is nearly as nice as me  )

[agentr31]

man!!!! you get tyres that dont affect the rolling diamater...

use the tyre calculator dazzler gave a link to...

[Rattler]

Thanks for the link and the advice everyone!

Cheers,
          Rattler

[bumpkin]

Ot at the very worst buy a cheap gps with speed readout and use that!

[bobbyd]

I fitted 18inch wheels with 215/35 tyres- the speedo is nearly spot on, about 3km/h out at the most according to my gps and the odd radar speed check sign have come across.

Usually factory calibration errs on the side of reading a higher speed than actual- also meaning you clock up mileage higher than actual.

[Master_Scythe]

2 tips:

1. Weigh your wheels. We get full size spares here in aus, weigh it, make sure your new wheels come out lighter. That way you KNOW you're getting better performance as well as looks.

2. Second hand, with no damage, will save you a FORTUNE. though you cant always find the ones you want