I've spent quite a bit of time searching for this answer but no such luck. Therefore I was hoping some of you might have it instead.

I'm planning on moving up from the 16" rims to the 18" rims in the near future. However, how will this effect my suspension? i.e. will I have to adjust it to conform to the bigger wheels? Or can I just switch them out and go on my merry way?
I'm not looking for performance enhancements, just want to make sure the car doesn't suffer b/c of the change.

Personally, I really like the stock 18" wheels and if I can get a good deal would take those as opposed to aftermarket wheels.

 

make sure u get a wheel alignment after your change, or improper tyre wear will occur.

and you might find your car's acceleration will decrease due to the bigger and heavier rims. the ride will also be stiffer from less rubber.

does that help?

 

Zephyr, it does thanks. Not too happy about the loss of acceleration due to larger/heavier rims but it's obvious.

So as far as adjusting the height of my vehicle nothing will need to be done right? Just swap out wheels, align and go?

 

Heh, I need help on this same very subject.
I'm planning on going from 16" to 18" in a couple of months.

 

The suspension hieght is the same between all the RX8 models. You will be able to bolt the larger 18" directly onto your car. There should not be any modification required.

one way to get away from the adverse effects of the larger diameter wheel is to use a forged or lightwieght wheel. They may be a little more expensive but you won't feel as much difference in acceleration and braking.

 

The diameter of the 16" with tire should be the same as the 18" with tire. If you want performance you're better off with a smaller wheel on the 8. It doesn't have the torque for a wheel larger than 16" anyway unless you're going to add that as well. If your car is an automatic I wouldn't even consider going to a larger wheel.

 

If the AT 8 dont have the torque to pull the 18's then why would mazda make this a option when you buy a AT 8?

 

For appearences. The stock MT doesn't have the torque for 18's either. With an MT your better off going down to lighter 17's if you want to maximize performance. If you're adding power that's a different story.

 

I guess 17" would be better then. But, I don't think the tire pressure system would work right? I was watching that RX-8 video it brought & it warned about buying aftermarket tires. --

 

After reading all your threads, I think I'm going to stick with my 16's. I really don't want to drop in or around $1k for new rims & tires (preferrably stock 18's) and lose acceleration.

I also don't want to pay more $$ for lighter weight 18's to compensate for the torque.

 

The loss of acceleration will only happen if the rims are heavier and wider than the stock your using now. I'd imagine braking might take a few inches longer to stop mind you inches not feet here since they are bigger than our 16's (I have the base model to whoohoo UGH!), forget the exact reasoning and dont care to find the reason atm lol.. Pretty much if you want grab a cord, let it hang down a few inch's say 6 and spin it around then try to stop it.. then hang it down a foot and try to stop it. Notice how the foot long try took a bit longer to stop? lol. I usualy hold true to a friends advice, once you go beyond 19's you should upgrade everything or you'll feel it soon or later.