Seriously though, I only remove the spare 90% of the time, sometimes the tonneau, only once did the tailgate.
My biggest change is going to smaller/lighter 17" alloy wheel and shorter DR's for a 5 fold Huge advantage.
(tire is a 27.5" tall 30lb DOT legal M/T ET Street, wheel is 30lb 17"x9" Aluminum Moto Metal 951)
Lower Rolling Mass
Effective Gear Ratio Reduction
Lower Ride Height for improved Aerodynamics
My 4x4 Ram with 17" DR's (all 4 corners)
is a half second faster than running stock 20's
30 pounds lighter per corner = 120 lbs less
effective gear reduction drops from 3.55:1 to 4.30:1
ride height drops by almost 3"and looks more like lowered 2WD Ram
I've only tried without the tailgate/tonneau once and it didn't make much difference, maybe a 10th, not worth the trouble compared to a tire swap