I seriously doubt it.
Bob's patent does describe using lift to reduce Crr:
http://www.google.com/patents/US5908217
I still doubt it because it takes power to create lift. It seems like it would take more power to create enough lift to lighten a trailer 15% than it saves in Crr reduction.
Best case (heaviest) scenario:
Tractor: 18,000 lbs., trailer: 17,000 lbs., load: 45,000 lbs.
Loaded trailer 62,000 lbs x 15% = 9,300 lbs lift.
Calculator says 94 rolling HP @ 55 mph @ 80,000 lbs.,
@ 70,700 lbs with the lift = 83 rolling HP and +.3 mpg WITHOUT accounting for the HP and fuel required to generate 9,300 lbs of lift.
http://ecomodder.com/forum/tool-aero-rolling-resistance.php?Weight=70700&WeightUnits=lbs&CRR=.0 08&Cd=.6&FrontalArea=100&FrontalAreaUnits=ft^2&Fue lWh=33557&IceEfficiency=.35&DrivetrainEfficiency=. 95&ParasiticOverhead=0&rho=1.225&FromToStep=5-200-5