As always, it depends on how you drive. But I remember hearing that if you reached 27 mpg on the highway in 4th gens you will be pleased with the mileage on the SS.
Note, if I've gotten any facts wrong in the above, just ignore any points I made with them
don't believe a thing you read about the next gen Camaro -- as history has proven time and time again:
WE DO NOT TALK ABOUT FUTURE PRODUCT PLANS PERIOD FbodFather
Camaro5 Fest sub-forum