So I found some slightly used wheels and snow tires for my speed3. They are Hankook winter I pike 205/55R16 91T mounted on MB Wheels seven x. According to this thread:
http://www.coloradomazdaclub.com/forums/showthread.php?t=2790

I can fit these on my car. But I apparently need "hub-centric spacer"s or "plastic hub-centrics"? I called Discount, they said they could help me, but when I showed up they said "We haven't sold wheel spacers for years". WTF? I told him I knew of 2 people who put the exact same wheels on the MS3, and got them from discount tire no less, but he still couldn't help me.

What do I need to get these wheels mounted?

Is the point of the hub centric spacer things to move the wheel outward, so that it clears the calipers (this is what discount said)? Or some other purpose?

How thin are thin balancing weights?

If they were balanced last winter, I shouldn't need to get them balanced again, correct?

Is it worth it to get them studded? I am planning on snowboarding a lot this year.

Thanks

Hello GGRR, Sounds like the employee didn't know what he was talking about, or felt it wasn't worth their time to solve your problem. The hub-centric spacers do not change the offset on the wheels, but rather only act to center the oversized bore of the wheel on your wheel hub. The wheels are bored larger than most of the vehicles they fit so that they can then be "bushed" down to fit many different vehicles. I would recommend calling or traveling to the Discount Tire store at 1990 S. Federal Blvd. to have them rebalance your tire/wheels and to mount them with the appropriate ring spacer. Tires/wheels soon go out of balance due to wear, loss of weights and/or improper initial balancing. I would have the balance checked and or redone just for the piece of mind, improved wear of the tires, and reduced wear to your suspension components. Regarding the "thin" balancing weights: I found that there was very little room (less than 1/4 inch) on the front wheels between the large brake calipers and the inside diameter of the MB wheels. The lead/zinc stick-on weights appear to be almost an 1/8 inch thick so they certainly should not be applied double thick. They should clear; as they did on my Speed 3. I got great traction with my Blizzaks, unstudded, and suspect that the ground clearance would be more of an issue. But I, being an old codger, take it easy on the glaze ice. Good luck. WINGSPD

Thanks to WINGSPD and 206b3 for the responses. I understand what's going on now. The word "spacers" is what threw me off. They call them hub centric rings at discount.

Just so you know there ARE such things are Hub centric wheel spacers which actually do effectively reduce your wheels offset.

Hub centric rings DON'T change offset.