When shopping for new RX8 wheels there are a couple critical issues to consider:
Weight. The Mazda RX8's fine handling and ride quality is very sensitive to what is called "unsprung" weight (which can best be understood as what hangs off the RX8 suspension rather than what sits on it). More than most automakers, Mazda tunes and equips its sports cars with very light wheels and owners should be very careful about keeping the weight down when they select replacement RX8 rims. Most RX8 owners can feel a deterioration of ride quality from a gain of as little as 3 pounds per corner in unsprung weight. We therefore strongly recommend that you use only light weight wheels for your RX8 like those we sell here. Unlike other vendors who rely on overly optimistic wheel weights as listed by the wheel manufacturers, we weigh each wheel that we sell to verify the lightness. For that reason, many of our listed weights here are slightly higher than the marketing weight listed on the wheel manufacturers' websites.
Offset and Size. RX8 wheel offset causes a lot of confusion. Here is a simple explanation. If the rim is 8 inches wide, and the mounting surface of that rim (backside of the bolt holes), is 4 inches from either outside edge, that rim has a 0 offset. To the extent that a rim's mounting plane is offset from that zero position, that offset is measured in millimeters for Japanese cars. The Mazda RX8 factory 18x8 inch wheel has an offset of 50mm. A 40mm offset choice is moving the track wider by 10mm per side. RX8 owners looking to stick to stock width can consider any of the offsets we offer here, but RX8 owners looking to go with substantially wider tires should stick to our 45 to 48 mm choices. For those looking to mount maximum tire width for autocross or track events see our 45mm 18x9.5 RP-F1 alloys which are lighter than stock wheels but allow 265/35, 275/35 and even 285/30/18s to be mounted on all four corners of an RX8.
Torque lugs to 85 ft/lbs and check that torque again every week for first month of owning new wheels or lugs.
Shop our RX8 2004-2011 Wheels catalog by clicking below:
Brian, just wanted tyou to know you've got another highly satisfied customer. I got my RoadstersportIII muffler on Friday, installed it in 20 minutes, looks and sounds awesome. I like the baffles out!! My new tires/wheels came Saturday, just got them on and test drove them. Fantastic!! And how they look--- just what I was after. I will add the front "mud flap" that looks like the rear one, for some stone protection, but the offset was just what I was working for. I'd love to send you some pictures for your photo gallery. If you'll send an adress via e-mail, I'll send some high-res photos showing clearances and side profiles, etc. The graphite spokes and polished rims really set well on my black car.
Thanks again, me and my wallet will be back!!
After reading many other positive reviews on both the GWR and Miata forums I finally decided to buy this product. My main concern for many months was whether or not I was up to the task of installing the header. But with the excellent instructions on Brian's forum as well as several Miata forum threads it turned out easier than I expected.
After receiving notice that the header would arrive on a Friday afternoon, I began the disassembly process. After about 3 hours I had the stock manifold out. Later that afternoon the new catted header arrived right on schedule. And it is a thing of beauty. I opted for the stainless version. Installation on Saturday morning took another 3 hours, although I could have shaved some time off of that but I was actually enjoying the process of double checking torque values and cleaning up my engine compartment. I already have the GWR catted midpipe, so that connection was a snap.
I put everything back together, reconnected my battery, and went for a drive. NO CODES! Nice throaty sound with my RSII muffler, and a significant boost in power and low/mid torque. Another happy camper here. I since have added a M-E tune and I feel I have realized all of the gains that Brian has achieved on his 2012 project Miata. I've put several hundred miles on my Miata since the install with zero problems. This is the car that Mazda should have built all along. Thanks Brian.