17-18\ rims

[mazda3 gx]

im looking to put 17-18\" \"ROH Blades black ice\" on my titanium gray 3 .i went to a site which has a tire calculator and punched in my tire size the the size i want and it said my speedometer would indicate a slower tha actual speed .my question is how do you put larger rims on the car if it affects the speedo or do i have to learn to live with it

thanks fo the time

[midnightfxgt]

Larger wheels will throw off your speedo.

There are two ways around the issue:

1. Deal with it :P
2. Get a lower profile tire, so that way the circum. is the same on both sets.

~JOHN

[majic]

what he said..

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

going from 15s 195/65 you need 205/50/17 225/40/18 you can just play with teh formula and as long as you get < 1% then u\'r ok (the speedo has probably soem +/- % from factory.. it\'s normal to have some variance..

[Dr Butcher]

Welcome to the ROH family! Bluntman and I will be so proud.... :)

As stated above, as long as you keep the circumference of the tire to approximate that of the factory tire size you\'ll be fine. As you upsize your rim, go with a lower profile tire. Play with the tire calculator to see what tires you can live with.

[bluntman]

According to the ROH website Blades top out at 17\".

[midnightfxgt]

Originally posted by bluntman


According to the ROH website Blades top out at 17\".

problem solved! :)

[Dr Butcher]

Yeah I noticed that as well, 17x8 is as big as they go. They have added a few new rims since I last looked.