Hi
i have a quick question in regards to putting 17's on my TL magna i have seen a few people have done this on the site.

what i was wanting to know is how much if any did it change your speedo reading ?.

thanks guys in advance

17's are 100% fine, that is what is fitted to the VRX and VR's as long as you get either a 225/50 or 235/45 tyre there is no difference in speedo readings

if anything your speedo will read slightly faster than wot your going as the 17"s will be slightly smaller than the stock 16"s

jaz

your overall circumference should be the same, because as you get larger rims, the profile of the tyre placed on the rim becomes smaller so the overall circumference of the wheel is the same as the factory.

So your speedo shouldn't change at all, but if your really worried, check using a GPS.

ok sssssh now.


Go HERE:

tyre calculator (http://www.miata.net/garage/tirecalc.html)

all you will ever need

ok sssssh now.


Go HERE:

tyre calculator (http://www.miata.net/garage/tirecalc.html)

all you will ever need


You the man... That link is great... :D

ok sssssh now.


Go HERE:

tyre calculator (http://www.miata.net/garage/tirecalc.html)

all you will ever need

Nice Link, I put in a comparison between my old treads and new and the calc claims a 1.8% difference, So when I am travelling at 100 Kmh i am actually doing 98.2 Kmh, I am going to check to see if thats right. Nice find too, thats a handy tool.

Nice Link, I put in a comparison between my old treads and new and the calc claims a 1.8% difference, So when I am travelling at 100 Kmh i am actually doing 98.2 Kmh, I am going to check to see if thats right. Nice find too, thats a handy tool.

thats the better difference to have. I always think its better than, if anything, you are going slower than your speedo shows. On my last car i paid no attention to all those calculations, and i didnt see a speed camera and it flashed, looked down and was doing 70 in a 60, and thought, oh well only a small fine. turns out my speedo was out 6% so i got the fine in the mail and it was 74 in 60, bigger fine and more points.

my 235/45/R17's are only 0.6% out on the magna :D

the calc claims a 1.8% difference, So when I am travelling at 100 Kmh i am actually doing 98.2 Kmh,

thats ok, you're speedo is allowed to be within 10% of the actual speed from the factory so the difference is minimal

yet apparently Vic cops are setting they're radars to 5%

yet apparently Vic cops are setting they're radars to 5%

Damn! That's rude! :shameonyoubastardssmiley:

We need more smilies :D

http://www.1010tires.com/TireSizeCalculator.asp
Another good tyre calculator.

thats ok, you're speedo is allowed to be within 10% of the actual speed from the factory so the difference is minimal

yet apparently Vic cops are setting they're radars to 5%
http://www.aussiemotorists.com/misc/msa-speedo.html
This is an interesting paper written on speedo accuracy, mentions the Vic cops too!

thats ok, you're speedo is allowed to be within 10% of the actual speed from the factory so the difference is minimal

yet apparently Vic cops are setting they're radars to 5%

the 10% law doesnt exist anymore :(