Originally Posted by boostmonkey

The RE-11A is the new version of the RE-11. The tread pattern is the same, but the compound has been updated. Bridgestone and independant reviewers are claiming the RE-11a is even faster than the already excellent RE-11.

Bridgestone RE11A: A New Suspect Has Entered the Crime Scene

The SCCA reworked all their autocross classes and will have a 200 treadwear minimum for all the street tire classes starting in 2015. I think it is a little suspicious that the RE-11 was rated either 180 or 200 treadwear in different sizes, Bridgestone claims improved grip with the new compound, but the RE-11a is conspicuously rated 200 treadwear across the board.

I wrote a more thorough review over in this thread:

Extreme Tire Reviews, Summer only, Dry, 220 Treadwear MAX