The stock RX-8 tires on RX-8 18x8 wheels (225/45R18) will work on a 6, but not ona 3

For the 3 you need a 225/40R18

 

If I'm getting 18 x 7.5 wheels for my Speed 3 what offset should they be?

 

52.5mm is optimal, I believe 48mm will still work. I used to work with some of the Engineers over at Mazda and they did a tire swing study on the 3 to see what was the biggest wheel that fit properly. 18x7.5 w 52.5mm offset was the result. I'm sure there are others out there that have slightly different offsets that may work (although some people rub without knowing it....my 17x7 60mm offset rub at the front tires, full lock at the 3 o'clock position of the tire, but it rubs on a "friendly" surface and I hardly ever have it at full lock.)

 

if I'm looking at some 18x7.5 wheels with a 42mm offset will these work?

 

so then i can use RX8 rims no problem, i just need new tires??
how much will a set of tires cost?? like for all 4??
and will there be any rubbing??

 

RX-8 wheels should work fine (I've seen them on numerous 3's), people either run a 225 or 215/40R18 tire...You'd probably rub in a similar fashion as to what I experience on my car. I've got 49,000 on my car now with no problems with the tires due to the rubbing I experience.

Depending on the brand/type tire, you should be able to get a decent tire for around $150 each or so. If you want any kind of mileage out of the tire, you should target a wear rating of 300 or higher (lower numbers wear faster, but handle better.)

Not sure if a 42mm offset will work or not....Best bet is to go to a local shop and do a test fit. 42mm would probably require you to roll the fender lip a little in the back wheelwell to avoid scrubbing the tire as it compresses into the wheelwell (this can be done at just about any body shop) Look inside the wheelwell and you'll see a 0.5" flange that would get rolled back on itself (currently sits at 90 degrees to the sheetmetal.)

 

i probably wont be lowering it... so would that make a difference??
and is rolling the fender lip hard?? like, im sure my friend and I could do it, cuz he's taking autobody classes right now....

 

Lowering changes the fita little, but not that much. Mainly at the front, when you are turning the tires. I'm lowered and where I rub has nothing to do with the ride height of my car.

I've never personally rolled a fender before, but there are specialty tools that can do it with no body damage (I've heard of people using a bat to fold the lip up, but I would hesitate to do that if you don't know what you are doing.) You basically fold that fender lip back in on itself to buy yourself an extra8-10mm of clearance to the outside edge of the tire.

 

yeah, i looked at my fender today, and im sure my friend could help.

and i went out rim browsing today, just for curiosity, and new 18's, with tires, are gonna cost me at least $1500, which i dont want to spend.

so i think my best bet is to go to tirerack, or somewhere else that has package deals (wheels, tires, and balancing)...

and how much do you think shipping will cost me?? (im in canada btw, so tell me which currency so i dont get misleaded.)

and i was told the 18" tires would cost me about 140 each

 

Hey Dentinger, try www.wheelmax.com as they are always running specials on rims and tire packages and shipping is free on certain purchases. I am not sure if that includes canada so you might want to call 1st.