Can I run this setup for my rear tires?, do i will have rubbing problems, power loss or something like that?, let me know please, thanks!!

(By the way, I searched a little bit but I didn't found anything sorry)

 

You can, its no big deal, a little off from standard size.

The proper size would be 245/40/18.


BTW, you shouldnt run different sizes front and back. The RX8 is not a Camaro or Porsche, its made to be a balanced car and equal tire sizes front/back is what this car needs.

 

Your speedo will be a little off
http://www.miata.net/garage/tirecalc.html

 

Big differences front/rear will also set the DSC/TCS off much more often, even when driving normally.

 

I'm running 245/45/18 tires on +35 offset wheels and have never rubbed. You'll be fine.

 

pretty big sidewall though...go w/ 245/40 to be closer to stock sidewall height

 

this is the important point..

beers

 

no you wont lose any power by changing tires; by rear tires do you mean you're running a staggered setup with your stock rims?

 

yep, i just bought this used tires because my friend sold me this 2 tires for 29 bucks , by the way at this moment my rear tires (225/45/18) are like a condom , that's why I'm asking this.


P.D: thanks for the info to all the users that answer me!!