i got my 255/45 fk452s with my 18'*, pictures to be posted soon

but just theoretically.. if i happened to get 255/40, the spedo would be off by 4.2%.. is there any way to have someone recalibrate it?

intense sells a recalibrater box... check there site.. or if you get a pcm reflashed i THINK you can get it set for diff size tires... or it might only be if you buy the programer and do it ya self.. but either way, yes it can be done..

alright great, thanks. i foudn the recalibration thing but is that only for stock?? it says "because factory cars can be off upt o 4%!!" so is it possible that i set it to my current tire size??

It'* mentioning the difference I see between speedo and hud (I believe).

My hud will say 65 and my speedo 62. There is mechanical error in most of our gauges.

I have the recalibrator in my car for my trans gear change and also when I put on my summer tires. It'* good and easy to work with. I'd recommend it. to date I have had zero problems with it.

I asked about this a while ago and Pat listed this site to see how far off you would be.

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