After looking at the brochure for the 8, I noticed the 18 inch wheel design incorporates a "fan blade" effect with the leading edge of each spoke tilted slightly inward. A cool nuance, indeed, but what affect does this have on rotating the tires? A diagram for you to follow:
The stock setup with the 18 inchers has the wheel spokes like this:

/ /

/ /

but when you rotate the tires, it'll end up like this:

\ \

\ \

thats with the standard practice of rotating wheels front to back criss cross...

but if someone were to mess up:

/ \

\ /

I guess all you can do is make sure the blades are all traveling in the right direction when changing tires and such! Any ideas as to whether the directions would mess up any sort of heat dissipation?. To see what i mean, refer to page six (red side) of the rx8 brochure witht he Ti grey and red cars. At least its not as bad as the z4 2.5 "turbine wheels"...

The tires on the RX-8 will only be able to be rotated front to back, because there is a proper 'left' and 'right' tire with a different tread for each side.

Thus, you can't rotate side to side.

Originally posted by Hercules
The tires on the RX-8 will only be able to be rotated front to back, because there is a proper 'left' and 'right' tire with a different tread for each side.

Thus, you can't rotate side to side.

You can always have the tire dismounted and remounted on the opposite side rim.

Many thanks, Herc, on the clarification!

Originally posted by Superfan


You can always have the tire dismounted and remounted on the opposite side rim. Imagine doing that every 5k miles or whatever... *grin*

And no prob for the info... it's pretty much the same on all high-performance tires.

Most, if not all, unidirectional tires will have an arrow embossed on the sidewall indicating the direction of (forward) travel. Also, I thought that all modern radial tires were unidirectional now - not just hi-perf. ones? Might be way off on that last one...

Originally posted by Superfan


You can always have the tire dismounted and remounted on the opposite side rim.


true but you will be paying high amount every 3-5 months to do it that way.

When the demo RX-8 came to town last month I went to see it and 3 of the 4 tires were on backwards. Since it was only for show purposes the dealer did not care too much when I pointed it out.

Performance tires have an arrow on the sidewall that indicates the proper direction of the tire and if you put them on wrong the handling goes to pot and can mess up the tire.

High performance tires are mostly directional, but not all radials are. The OEM tires I got with my Miata were not.

To all those who get their RX-8 in the next month or two, when you get your car check the tire pressure. Many people who get a new Miata say they handle baddly when they come off the lot, only to find that they still have 40psi in the tires instead of the recommended 26-30. 40 is used for shipping and storage to prevent the tires from flat spotting.

Originally posted by Hercules
The tires on the RX-8 will only be able to be rotated front to back, because there is a proper 'left' and 'right' tire with a different tread for each side.

Thus, you can't rotate side to side.


I always had all my cars tires rotated back to front / front to back.

santino, rim design doesn't matter. If the blades face forward or back...left or right as long as they are bolted up properly and the TIRE is spinning the right direction, your fine.

Actually, the Rims on left and right are not "mirror imaged", so the car would still look the same even after tire rotation (ignore the performance tire's direction), unless the production car rim has different plan than what the picture shows. But the performance tires like other said are directional.

http://www.mazdausa.com/MusaWeb/rx8/images/gallery/rx8_images_18.jpg

http://www.mazdausa.com/MusaWeb/rx8/images/gallery/rx8_images_12.jpg

Why would you rotate?
The Rx-8 has a 52/48 unladen weight distribution, with rear wheel drive and electronic brake force distribution, and the inherrent understeer from its torque sensitive differential, tire wear should be equal at all corners.

http://www.bmwusa.com/site_layout/joy_of_driving/technology/featured_content/rwd/rwd.cfm

http://www.bmwusa.com/site_layout/joy_of_driving/technology/featured_content/near5050/5050.cfm?link=5+Technology&url=site_layout/models/technology/5tech.html

I know that fan-like design should help with brake cooling but doesn't it screw up the vehicle's aerodynamics / airflow?

Originally posted by MikeW
Why would you rotate?
The Rx-8 has a 52/48 unladen weight distribution, with rear wheel drive and electronic brake force distribution, and the inherrent understeer from its torque sensitive differential, tire wear should be equal at all corners.


the reason you rotate is because each tire makes a different number of rotations while driving. If you were only going in a straight line forever then you wouldn't ever need to rotate. The wear may be better on the 8 but keep in mind that the steering tires will be taking more stress and wear faster. Unless you are going to do burnouts like crazy then the rear tires should last a pretty long time.

Originally posted by neit_jnf
I know that fan-like design should help with brake cooling but doesn't it screw up the vehicle's aerodynamics / airflow?

the vehicle's airflow, no. But it may effect the cooling of the brakes if the rims were designed for that purpose, but otherwise I don't see it happening. Idealy, if you want to reduce some of the turbulent air around the wheels (but don't care about cooling the breaks) you could design a rim that is a complete circle on both sides. Therefore no matter where the wheel is it still has the same profile to the airstream.

This is so neglegible though that things like the exhaust and suspension parts put up much more of a fight against aerodynamics then the wheels would. If we were trying to make the rx8 fly then this would be a problem but while driving on terra firma don't worry about such tiny problems.

the rx-8 is 50/50 unladen weight dist.
________
COLORADO MARIJUANA DISPENSARY (http://colorado.dispensaries.org/)

Originally posted by Farsyde


the reason you rotate is because each tire makes a different number of rotations while driving. If you were only going in a straight line forever then you wouldn't ever need to rotate. The wear may be better on the 8 but keep in mind that the steering tires will be taking more stress and wear faster. Unless you are going to do burnouts like crazy then the rear tires should last a pretty long time.



just to add to taht a bit, front tires generally wear out slightly slanted...more so on the outside due to cornering and rear tires wear out more flat, its' ever so little but makes a difference if you never ever rotate them...tho if we're all using like re040 and s-03's may not get to that point =p

Originally posted by lefuton

...tho if we're all using like re040 and s-03's may not get to that point =p

curious....are you a wrx driver, lefuton?? :D

The 5 spokes on my Probe have the same directional type design...


Funniest thing is when you get new tires and the tireshop doesn't realize there is a correct direction to the rim and mounts your directional tires on whatever rim they feel like... so 4 months later like me you realize you have 2 backwards rims and the tireshop refuses to remount them and now you have the imfamous Probe "backward wheel mod" :p

Guys - the original poster in this thread is wrong. The RX-8 18" wheels are NOT directional, there is no left and right side wheels. They're identical, the same wheel at all 4 corners. Don't worry about it!

Regards,
Gordon

the original poster in this thread is wrong

actually, my friend was the one who posted this topic on my account.
so technically HE is wrong. :D

santino

Hi Gord,

You may be right about the production cars but the one I saw in the showroom, touring/promo model, had directional tires, and they were on backwards on 3 of 4 corners. The arrows were pointing towards the back.

My es 100's cost me about 150 CDN per corner in 16" for my Miata. And that is at a discount for ordering them through the states. They were asking over 200CDN per corner down the street. Hate to think what 18" performance tires are going to cost. Have you checked out the prices yet?

Originally posted by pr0ber
The 5 spokes on my Probe have the same directional type design...


Funniest thing is when you get new tires and the tireshop doesn't realize there is a correct direction to the rim and mounts your directional tires on whatever rim they feel like... so 4 months later like me you realize you have 2 backwards rims and the tireshop refuses to remount them and now you have the imfamous Probe "backward wheel mod" :p

lol, that sucks. Prolly looks hipnotizing driving down the road :D

Originally posted by Midnight Flyer
You may be right about the production cars but the one I saw in the showroom, touring/promo model, had directional tires, and they were on backwards on 3 of 4 corners. The arrows were pointing towards the back.

My es 100's cost me about 150 CDN per corner in 16" for my Miata. And that is at a discount for ordering them through the states. They were asking over 200CDN per corner down the street. Hate to think what 18" performance tires are going to cost. Have you checked out the prices yet?

Yeah, the tires are directional, but the wheels aren't! How can a car straight from the factory have the tires mis-mounted? Sheesh!

I'm scared to check the price of 18" tires - I've done some preliminary looking for 16" or 17" winter tires, and those are scary enough! :eek: ;)

Regards,
Gordon