I highly doubt you can do cylinder de-activation with this engine. there are only a few engines on the market that have that capability and from what I have read in other forums, I'm not sure people are seeing the fule savings that have been touted.
the best thing you cna do with this engine to save fuel is keep it tuned, keep the fluids changed and watch your speed. this engine gets thirsty if it has to downshift too often on the highways. (the rolling hills on 83 kill me) Otherwise 27-28 mpg on the highway is not out of the ordinary. that is not too far behind vehicles like the Accord (4cyl.), Corolla, jetta, etc.