Actually, the consensus on the posts about mileage is that mileage
does improve after 20,000-30,000. 
(I've already gone up to around 30 mpg on long runs on the 2006 NA/manual tranny
soonercruiser. And she only has 23,000 on her!
The 2006 GT HO turbo vert is only getting around 24, at best; but only has 11,000 on her.
