During WWII the German's used a machine called ENIGMA for sending messages and confuse the Allies. Enigma might be good title for this subject.
Reviewing my 2019 sales brochure, it states that the 23-gallon fuel tank is "included with 5.7L V8 eTorque 4x4 Crew Cab short box on Tradesman, Big Horn, Rebel and Laramie." (See attachment) This implies to me that 23-gallon tank was standard for those configurations.
For the 26-gallon tank, the list begins with the word "Add," which seems to imply it was an option and in the block next to the entry the letter "O" only appears in the Big Horn column.
The 33-gallon tank says it's "included with 8-foot box models, not available on Regular Cab short box models..." (Of course there wasn't a 8-foot box or Regular Cab in 2019.) "...optional with H1, H2, X1, X2, P1 and P2 Equipment Packages."
My apologies for the poor scan of the brochure, but if you zoom in you can read it. Of course between the time the brochure was sent to the printers and production started things could've changed. Likewise for 2020 and 2021 models.
Best regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 03 June 2018. Now at: 045590 miles.