M3 vs Mtech ti front sway bar diameters?
 

Can some one tell me if these front bars are the same diameter?

According to realoem
26mm ti Sport
23mm M3
Note: The mounting points are different. They are not interchangable AFAIK.
http://www.318ti.org/forum/showthread.php?t=10740

The M3 ones attach to the shocks themselves, the normal ones attach halfway through the suspension arm. Obviously this gives the M3 ones a lot more direct (better) way to work, which means that the M3 bars, although thinner, are able to probably put more strength onto the wheel.

Some coilover kits have the brackets to allow for the M3 style bars. KW ones do, at least.