Not sure if this is a repost but EPA figures are on the EPA website for the A5.
 

It looks like the site might be a little messed up right now though. They have 4 cars listed 2 manuals and 2 automatics.

Automatics are listed at 18 city 26 hwy or 18/27 with a gas guzzler tax?! (The site must be messed up.)

However this does indicate a 1 mpg increase over the current A4 and A6 3.2.

Manuals are 16/26 or 16/27.