Explain to me what makes the various poly bushing companies different?
 

Whiteline, Energy, Prothane, etc.... What makes the different? Are certain manufacturers softer vs. others? Any idea why so many come out of Australia?

For the most part price...especially in the case of Whiteline.

There can be differences in the compound, durometer mostly. Many companies list what duro they offer. Higher numbers are stiffer.

And because us Aussies are awesome...

Not Beatrush - from Japan baby!! :thumbup:
But seriously, the main difference is the durometer rating between each of the bushings. (Some are softer/harder then others (thats what she said :bellyroll: ) ) and the compound mix that they use to create it.
Example the durometer rating = Soft/Hard (Hardness level of the actual bushing)

Australia is known to be heavily involved with course/track/rally oriented events. Therefore a lot of competition.

The only two durometers I've seen noted are 75 and 95. I belive many stock parts are 45 or 55.

Curious, is the durometer measured as a scale of something, i.e. 45/x vs 75/x?