Here are the Rolex GT series 2008 rules for tires. Doesn't sound like they are staggered, but I could be wrong.

Bob

All GT Dry tire sizes are the same as wets with the exception of the 305/685-18 where the wet
sizing is 305/690-18.
Tires must be ordered two weeks prior to the event.
6-1.2 Wheels - All four wheels must be 18-inch diameter.
6-1.3 Carbon fiber and wide-five wheels are not permitted.
6-1.4 Wheel fans are not permitted.
6-1.5 Centerlock wheels are not permitted.
6-1.6 Wheel centering or hubcentric devices may be added.They must be bolted or
mechanically retained to the hub,(no floating spacers).The centering /locating device
up to three inches in length must not protrude beyond the outside wheel rim flange.
The wheels studs can be a maximum of two and one half inches in length and must
be at least one half inch shorter than the centering device.

Like I said. i could be wrong. Here is some more info that looks like they can stagger.

Bob

GRAND AM Rolex D.P. and GT Recommended Wheel Rim widths

Slick

Tire Size
Rim
Max inflated diameter
Section width
Tread width
DP sizes 325/650-18
12Jx18
648.7
333.5
304.0
325/705-18
13Jx18
706.6
352.6
304.0
GT sizes 245/645-18
9.5Jx18
651.6
258.3
240.0
285/645-18
11Jx18
649.4
294.7
255.0
305/660-18
11.5Jx18
660.2
318.3
283.0
305/675-18
11.5Jx18
675.5
319.9
295.0
305/685-18
11.5Jx18
686.9
322.4
295.0

Here are the specs on the SpeedSource RX-8 wheels

SuspensionDymanic Suspension DSSV shocks
Front and Rear adjustable anti-roll bars
18x11 Racing Hart wheel front with 285/645-18 Pirelli Racing tire
18x11.5 Racing Hart wheel rear with 305/660-18 Pirelli Racing tire

Those are staggered, but barely. Bottom line is for track use, Speedsource found this staggered fitment to work best. Is there a science as to why they chose a 20mm smaller tire for the front than the rear?

I figure they may decide on sizes based on type or track and/or conditions?

For what its worth, I have run stock rubber and it sucks both the bridgestones and the dunlops

I have run FK452's 245/45 all around and it was much better

I now run Toyo T1-S's (yes I know they are discontinued, it was awesome to find a set) at 245/40 and 275/35 and Iw ouldnt trade this setup for anything, perfect balance for the car, and I installed my Tokico D spec's and swift spring today and its a million times better, I do alot of low and high speed mountain driving, so its not like I am driving straight lines.

for a street driven car Id add a stiffer rear sway bar if you go staggered and adjust until you get the neutral back. Understeer and sports car is an oxymoron. Turbo a civic if you want that safe for John Q Public front end wash out.

Exactly!!! newguy couldn't of put any better, understeer and a true sportscar is an oxymoron, when do you hear other sport car owners complain about understeering in their sports car?! C'mon guys thats what the car is about. You might as well start an argument of making the 8 all wheel drive. I prefer the way it is and I'm sticking with my 19x9.5 in the back and 19x8.5 up front.

I regret having my "unstaggered" wheels...
now thinking of changing to staggered wheels w/ aggresive offset....

I can attest to this being a great setup for most uses. I currently run Nitto Invo 245/40/18 front and 275/35/18 rears, and I love the way the car drives. I can still get the car to rotate at the high rpms of 1st, 2nd, and in 3rd it's almost completely neutral. This is a really safe setup for most drivers. If you stay with the same size and rotate the car too much, you essentially lose some speed depending on the turn or what you're actually making the car do.

For the track racing I've done so far, I think in the low power areas I would be happy with a 255 front tire, but I love the 275 rears. Its very safe for the street and allows you to push the car to the limits without risking too much.

I have the video on youtube showing the car's characteristics on an actual race track. Note that I only got the car loose a few times. You can break it loose pretty easily with fast transitions under braking, but this is a pretty unsafe manuever. You'd see in the video that I kept the wheel pretty smooth for most turns.

http://www.youtube.com/watch?v=9HJqPPezIFI

I have 2 sets of staggered, when I bought my car in 2003 I got tired of the bored cornerings, while any other cars with staggered whipped me, unbelievable.

I bough up my first set, and ever since I never went back to standard or equal size, I use 245/35/20 in front and 275/30/20 in the rear, obviously I replaced my suspension for the Megan Coilover Kit, upgraded to Adjustable Front & Rear Camber/Toe Kit and must say and admit I experienced a huge diference in handling.

My opinion is nobody should complain not using staggered if they havent experienced them with the right set up and parts needed to ride staggered, you can ride staggered with OEM set up and feel a small diference or invest properly and never regret it.

Everyone thinks diferent and by the way, by no means RX8 can be compared to the results of other cars, like 350Z, EVo, STI etc.. people should know that Rotary is a totally diferent car and engineering. The way it was developed made it's unique taste to each owner in this world,

Everyone knows how to make a sandwich it's what they want in it that makes the diference. jejejee

Sway bars for staggered tires
 

So I bought my RX8 with some really nice aftermarket wheels with 245 40 18 rear and 225 40 18 front. The car understeered really badly. (My neon with the tokico kit cornered much better if you can imagine that). Added Bilstein HD struts and then the Hotchkis adjustable sway bar kit. Going through the adjustments I found neutral cornering with the front bar on the softest of the 3 settings and the rear on the stiffest setting. Just a tad of over steer at maximum conditions. Then a front sway bar end link separated and I replaced with the Racing Beat HD end links and am quite satisfied with the result.

I have a question. I just bought 2 fronts for my 8, 225-45-18 Kumho SPT's. I want to go with the staggered look on my car and I am about to order the two rears. If I went with 255-40-18's would they fit? also, would the car set level? I have the stock black chrome 18's and dont really want to change out the wheels so will the 255's fit a stock wheel?

Ive read and some people say dont go any wider than 245's but others have said 255's were ok.

I think that 245/40-18s are the widest recommended tire for the rim. Going wider than that compromises your safety. Some folks have 275s on stock rims for racing, but my understanding is that the sidewall on racing slicks are harder than street tires, and therefore its less of a problem.

I just ordered 245/40ZR18 Dunlop Direzza Sport Z1s for the rear, I went to swap out the Dunlop Winter Sport M3s that I have and noticed the Bridgestone RE040s were close to bald. So looks like I'll be running Bridgestone RE040s up front at the stock size, with the Dunlop 245/40ZR18s on the rear. Unfortunately, the RE040s up front are practically brand new, hit a nail last fall and the Mazda extended warranty replaced one, and I had to cough up the dough for the other. Unfortunately the dealership would only replace like for like. So it'll look a bit odd for awhile :)

I have stock wheels wrapped in Falken FK452's in 245/45R18s and I find them to be more than adequate. My RX8 is my every day driver and I autoX my car on the weekends. Those tires aren't great for AutoX but for everyday street driving and corner carving, they are great. The car rides smoother than stock with those tires, and I feel as if I can push the car more, but at the limits I can feel the fronts give up a little adhesion to the road. Any thoughts as to what might be a better set up for the car?

I do have Hotchkiss Racing Sway Bars.

Yeah man do not put 255 on the stock wheel. Most people who are staggered have a wider wheel and tire in the rear, not just a wider tire. IMO just go with the same 225's in the rear.

hey guys sorry im a fair noob when it comes to this stuff.. i just got my vertini hennessay 20 by 8.5 and 20 by 10 inch on the rear.. im confused the guy who fitted them put 255 on the rear on a 10 inch rim with a profile of 20.. he reckons the 255 on a 20 inch wheel is as wide as a 19 inch wheel that is 285 or 275. some thing along those likes ccan some1 explain cos i measured my tyres and there about 285 wide . but the tryer is 255????

its coz the tires are stretched and IMHO thats not a good idea but im no expert ..

Not gonna lie.
 

His car is mad tyte.

You guys make me laugh

When a car is as balanced as the rx8 is, stuffing bigger tires in the back than the front WILL make it understeer more... it won't make it "more balanced" or "handle better." I run 10.5" in the back and 9.5" in the front, but you will never hear me try to justify it with any kind of improvement in handling. I love how it looks and THAT is why I wanted a staggered setup... 99% of it's life will be spent on highways, so what the fuck do I care if it understeers a little.

Stop kidding yourselves... stop giving a shit about what other people think and do what you want. Not everything in life has to be practical...

This is retarded. Honestly, there are way too many factors to determine what is the "best." It's all about what works for you. Do something, if u like it great, if you don't, try something else, till you find something that works for you.

Are we taking track cars? Or Daily Drivers? Combination of both?

It will all come down to what you expect from your car, that aside. I would review tire quality before looking at staggered offset. Followed by, stock or boosted RX-8? The TQ output and what you are doing with your car are what's going to make the noticeable difference in the offset. From what the article and responses look like, it's about handling. I would have to say it's probably better to look at better quality tires before going to a staggered offset.

I would have to agree, as my first post for the rx8 club!

:)

OP's link is dead.

what if I could get Staggered rims at 552 shipped
18X8.5 and 18X9.5???

would that be worth it?

Why can't you get four 8.5s or four 9.5s?