It would have to be extremely light. Payload for the R1T is 1764lbs. Once you put 4 people in the truck, that likely reduces it to 1000lbs. For a 5th wheel you need to have 20-25% of the trailer weight on the hitch, so maximum of 5000lb. The truck bed is also aluminum and I am not sure how much structure is under it. Also keep in mind the 5th wheel hitch also takes up payload.Has this been answered by Rivian? Will the R1T be able to pull a 5th wheel?