Extracted from this EPA "Advanced Vehicle Testing Activity" report performed by Intertek for Idaho National Laboratory (INL):
http://avt.inl.gov/pdf/ice/fact2014chevroletcruze.pdf
Energy Consumption at Steady-State Speed, 0% Grade
10 mph = 38.1 mpg
20 mph = 54.0 mpg
30 mph = 68.4 mpg
40 mph = 63.6 mpg
50 mph = 60.5 mpg
60 mph = 55.4 mpg
70 mph = 50.6 mpg
80 mph = 43.8 mpg
WHY can't EPA put such info (graph) on the new car window stickers?