I've been running them....haven't had any problems with mine. You'll "feel" the road a bit more if their are alot of pot holes.

 

Same here. I'm running the same setup and I have had no problems. The road is a lil more bumpy but thats what you get when you go with lower stiffer springs and a thinner tire. I personally like to feel the road underneath me.[thumb]

 

lol im kinda scared for 40, bumps and stuff, so what is the worst thing if i go in a big pothole? blow the tire? bend the rim?

 

Both lol.... That's the Worst Case though.

 

depends ont he rim... some rims are better quality. I run 215/40's and i'v hit some holes. i live on some shit ass roads and i'm fine. I might bump dowo to 205/40's next just to see the diff in ride height

 

ok im confused now.. so ur saying by getting 205s car is gonna be lower i know, but distance between the tire and the fender is gonna decrease also?

 

wait, maybe im wrong, but thats what i always thought, isnt 215 is the width of the tire, and 40 is the height? so im saying that ud stay with the same height of tire and just change the width?

 

first number is the height. That's why the 205 is a much lower profile than say a 225/40.

 

R U sure about that, I always thought first # was width, second number was height.[wrenchin]

 

ok my bad

 

you should have "more" room in your fender with the lower profile tire. It's a shorter tire. Not by much but it's shorter. So it won't be filling the gap so much. The svt uses a 225/45/17 i believe stock. Don't quote me. But when they lower their cars a good bit... that tire is too tall and wide for some drops so it could rub. I have a 1.5 inch drop and some with 215/40/17 with 40offset wheel and have not rubbed yet

 

alright, thx that sounds better

 

svt uses 215/45R17 tires

 

yup thats right, so 205 is width and 40 is the height

 

205 width in mm

40 is 40% of 205 that makes up the height

and 17 is of course the rim size

so if you want to upsize a tire you do +10 -5

so on the svt the stock size is 215/45/17

to go wider +10=225 and -5=40 will give you the same rolling diamater of the tire within a few mm

 

http://www.miata.net/garage/tirecalc.html used this pretty good thing