CMC 17" Wheel Weight & Welded Spacers

[Suck fumes]

exactly!

[DAlgozine]

This horse was beat to death in the CMC forum a few years ago when the Bulletin came out allowing a welded spacer to be included in the weight of the wheel, and the subsequent "End of the season rule debate" about it.
Good read. Get your popcorn.

But, here's what I come away with.
The Enkei wheels with spacer welded come in just over 18lbs.
The only way a 17 x 9.5 GM wheel can get close to 18lbs is a set of custom wheels, which cost thousands of dollars.
So, nearly all GM's buy Z06 wheels that weight 19.5 - 20 lbs and still have to install a spacer for another 3/4 - 1 lb, and that's about 20 - 21 lbs.

A few pounds doesn't sound like that much, but it is rotating mass, so it is a big deal. Plus there is another benefit of the Enkei with spacer. In order to make the minimum , it has more of its weight in the hub. And, that one is important also.

From what I have read, rotating mass weight is a factor of 10 when compared to sprung mass. So, 8-10 total lbs of rotating mass is equivalent to 80-100lbs of sprung mass. That's a big number. Some of that would show up on the dyno and get negated , but only a portion of it. Im not an engineer, so fire away. But everything I have read, indicates that rotating weight is a very big deal. As I'm sure some already know. Or we would all be using 26 lbs wheels.