I talked to Mazda to get the wheel size. 18 inch wheels, 8.0 inch width, bolt pattern 5 lug x 114.3cm/4.5in, offset 50.

I've been tryin to get replacment wheels, but can't find any that particular size, any suggestions?

 

If the RX-8 truly has a 50 mm offset spacers are worthless. Spacer can compensate for a wheel that has too much offset but not vice versa.

There are a ton of wheels with 45 mm offsets. These should be adequate. This lower offset will make the steering a bit heavier. They will also make the car look a bit more aggressive. I would avoid 40 mm or less offset since the steering will begin to suck. Excess scrub radius tends to reduce the transient response of the nose of a car.

A ton of peeps are gonna argue this but you better look for some light wheels, preferrably forged. Based on Mazda experience I bet the RX-8 wheels will be about as light a cast wheel as you will be able to find. If you go with a heavy aftermarket wheel the car will ride worse and have poor handling on rough surfaces.

For all those that go with heavy wheels or low offset wheels I promise that the sensation of reduced performance will overcome the initial joy of vanity or of saving some bucks. I know because I lived this myself.

 

Volk Racing has numerous wheels which will work. The RX7 (third gen) does have an offset of 50. I have 18x9.5's with a 45mm offset all around. Weight is 16lbs. :-) Light as air almost. The stock RX8 rims look rather ponderous, although judging by the overall weight of the car, I'm sure they're not much, if at all, over 20lbs. each. Volk's website is www.rayswheels.co.jp. Be forewarned, most of their aluminum anodized rims DO NOT hold up well to road conditions if used on a daily basis. Ask me how I know. Mine look like crap after less than a year.

 

My friend has these centerlines:

http://www.centerlinewheels.com/w_ca...hite_small.jpg

on his Volvo. Light as hell but still strong as hell.

They aren't the optimal fit for the car but look for centerline to produce other good rotary forged options in the future.

-Mr. Wigggles

 

I do not think its that much of an increase in ride discomfort if you have proper tires. I went from stock 15" to 19" and I love them, it looks so much better, of course its slow, but hey an automatic at 140 ish whp isnt gunna be fast anyways. I cannot stand small wheels -they look so horrible - plus the wheels are a crucial part of the cars appearance, it may not seem like it, but it definately is

 

same, i went from stock 15"(shitty *** bmw) to 18's and at the same time got lowering springs installed. felt so much better and handled/cornered so much better. i feel more connected with the road.

 

however, if u decide to upsize your rims.... PLEASE PLEASE lower your vehicle first, thank you!

 

The only thing, as stated above, is MAKE SURE THEY'RE LIGHTWEIGHT! Heavy rims will make your car stop slower, accelerate slower and handle worse. It's all about battling inertia, so you've got to remember that weight is the enemy! Especially unsprung weight. Especially especially unsprung rotating weight.

So, those chrome 20" rims may look good, but be forewarned, they're going to do bad things to the performance fo the car.

Car and Driver (I think it was them...I get too many magazines) did a test on what those big rims did to an SUV. I think about 2 less mpg (of course, if you buy an SUV, you already don't care about mpg) and, more importantly, a whole second slower 0-60 time. That's a lot.

With the lightweight (relatively), lower powered RX-8, you could really screw things up if you put on a set of anchors.

Okay, I suppose I've ranted enough. Now I've got to twiddle my fingers and weight...err...wait until the RX-8 is on the S-Plan.

 

I remember seeing a pic of your rims. Black with silver outer ring. Who is that manufacture? Thanks

 

Well I do not think weight and size necessarily mean decreased performance. If you have good tires, at proper PSI, then you should be able to stop if not better. Upgrading from 15 - 19" was quite a step, but upgrading from bf goodrich potenzas to pirelli p7000s there is a huge difference in traction. plus, if you are auto crossing or on the track, I HIGHLY doubt you will be rollin' on dubs or using extremely heavy wheels. magnesium and other materials are used to reduce weight of wheels.

 

I agree that size doesn't necessarily mean decreased performance. If you can get a 1" wider rim on without increasing the weight, then, hey, you'll probably get more grip. But, if you put on 19" rims (even if you maintain the same outer diameter of the tire) you'd be compromising on a lot of things. Unless, of course, you got ultralight 19" rims, but my guess is that they are out of the price range of most folks (like me). So, if the look of the bigger rims are worth the performance hits (braking, accelerating, maintaining grip on a rough surface) then that's cool. There is a reason that show cars all have big wheels...it looks good.

But otherwise you've got to realize that adding more rotating mass really hurts the performance of the car.

 

So I guess Newton's Laws of Physics do not necessarily apply to cars? Sure, more grip is better but so is less weight. Larger diameter wheels and more grip are not related. What is your point?

BTW, what other materials besides magnesium are used to reduce wheel mass from the normal aluminum?

 

Well, not only material but the design and process. I'd love to get a nice set of forged aluminum alloy rims, but they ain't cheap.

 

cheaper than mags.

 

The heavier the wheel the more rotating mass which means its harder to stop or get started. So unless you upgrade the brakes it would take longer to stop the 8 with heavier wheels.

 

The largest i would go is 19" because there are plenty of nice, affordable, high strength lightweight rims in this size (AXIS!!!). Also 19" is the largest rim size you can go while keeping the tire diameter the same as 18's and 17's therefore the speedo would still be accurate

 

i hav 20's that im selling cuz they rub on the 8. i wud need coilovers to make them fit right. if anyone wants them i have pics. let me know. they'd fit better on a 370z tho

 

Instead of posting in a NINE YEAR OLD thread.. You'd be much better off trying to sell them in the other forum... Umm, what's it callled? Umm... Oh yeah, the FOR SALE forum.

 

Whoa!!! 9 years of hibernation, then bamm!!! It's alive again...lol