Not that I dont beleive it but the only reason that I "THINK" is possibly true is that the small windshield causes less drag on the bike, and cruise causing your revs to be constant while riding....
Windshield and cruse control
I leaned that a small windshield and instalation of cruise control can increase your milage slightly. I was getting an average 49 mpg highway and now getting 50-51 mpg highway. Not huge increase but with todays gas prices it could same me some bucks. 
