Trying to understand CAT scale weights

[b1lanc]

Trying to figure out why my 3500 weighed in heavier then just prior to picking up the RV a year and a half later and first long trip mid May? Cab had a few more items (40lbs maybe) prior to the trips so I'm surprised that didn't show up. Most of weight drop is front axle? I also saw a drop in pin weight the heavier the trailer load was which confused me because the added trailer weight was ahead of the trailer axles.

Truck after purchase before RV ordered - Nov 2020
Front GAWR/Rear GAWR 5560/3460
Gross 9020

Truck day before picking up RV
Front GAWR/Rear GAWR 5480/3440
Gross 8920

Truck day before 30 day trip
Front GAWR/Rear GAWR 5480/3440
Gross 8920

Truck day before 43 day trip with 55gal Titan tank replacing 32gal OEM
Front GAWR/Rear GAWR 5580/3520
Gross 9100

 

[Rockcrawlindude]

100lb out of 9000lb is ~1% I would call that margin of error