I get about 2 mpg less with my '04 Dodge 4x4 DRW than my '96 Dodge 2x4 SRW. The '04 weighs 1000 lbs more than the '96.
My TC is 4000 lbs. My '04 DRW had upper stable loads on it installed by the previous owner. The '04 sits level with the 4000 lb TC. I was comfortable without a rear sway bar, but the wife was not. I installed a rear sway bar. I also installed airbags , but didn'nt need them and do not use them. I use OEM size tires. I also installed a 17000 lb Curt hitch.
I'm not concerned with the door decal weights, but I am below them if anyone is interested.