That one is a BIG,BIG factor riff raff.
I don't drive the VX hard,press the gas pedal little by little & let the horse gain speed enough to keep up with traffic,also use 93 octane fuel or 89,avoid using the 87 as much as i can.keep tires inflated to manufacturer's recommendations,avoid hard stops & hard accelerations,on high ways use your cruise control & avoid tailgating so no need to be braking constantly.
All those driving behavior helps improve mileage a lot.