What the 337RLS adds forward of the bath
From the rear wall to the bath, Grand Design's drawing for the 337RLS carries the same labels as the 303RLS: a tri-fold sofa across the rear, a 40-inch entertainment center, pantry, microwave over the range, and 16-cubic-foot refrigerator in the off-door slide, theater seating and a booth dinette opposite, and an island with the sink between them. The change is in the bedroom. The 60-by-80-inch queen sits sideways in an off-door slide, Grand Design lists a king as optional, a wardrobe runs across the front wall, and washer/dryer prep fills the front door-side corner. The awning forward of the entry grows from 13 feet on the 303RLS to 16 feet here.
At 35 ft 7 in the 337RLS is 3 of 8 on length and leaves 4 ft 5 in on a 40-foot pad. It is 4 of 8 on dry weight at 11,200 lb and 4 of 8 on hitch at 2,300 lb. That hitch figure is 20.5% of dry weight, 6 of 8 lowest, and it is where the layout shows up in the numbers: the 324MBS weighs the same 11,200 lb dry and adds a bunk room, yet its brochure hitch figure is 300 lb lighter.
The washer/dryer prep is part of the same question. It sits at the front wall, the end of the trailer that rests on the truck, so appliances installed there add to a hitch figure that is already a standard-build average. Check a truck's payload against the loaded number rather than the brochure one.
The 2026 Reflection brochure with the 337RLS drawing and figures →Setting the 337RLS beside the 303RLS, 320MKS, and 360FLS
Keeps the rear half and drops the bedroom slide, the king option, and the washer/dryer prep label. It saves 1,100 lb dry and 320 lb of hitch, and carries 8 gal more gray and 8 gal more black, 87 and 47.
Open record →Same bedroom, kitchen at the rearReflection 320MKSIts front bedroom drawing matches the 337RLS label for label: queen in a slide, king optional, washer/dryer prep, 16-foot awning. Behind the bath it turns into a rear kitchen with the refrigerator on the rear wall. It is 0 ft 10 in shorter, 100 lb lighter, and 100 lb lighter on the hitch.
Open record →Living room at the other endReflection 360FLSMoves the living room into the front cap with two facing tri-fold sofas and puts the bedroom and washer/dryer prep at the rear. It costs 3 ft 7 in, 1,188 lb of dry weight, and 300 lb of hitch, reaching 2,600 lb, the heaviest pin figure in the family.
Open record →Three checks for the 337RLS bedroom slide
- With the bedroom slide in, stand at the foot of the queen and try the front wardrobe doors and the washer/dryer prep door. The bed travels in the slide, so this is the room as it is at a rest stop.
- If the optional king is on your list, measure the floor between the bed and the door-side wall with the slide out. The drawing sizes the room around the 60-by-80-inch queen.
- Open the washer/dryer prep space and look at what is actually installed there, water, drain, and power, before budgeting for appliances.
Published 337RLS figures
Two official 337RLS weight sets, and the one used here
Grand Design's 2026 Reflection brochure lists the 337RLS at 11,200 lb dry and 2,300 lb hitch, and those are the figures on this page. Grand Design's current 337RLS web page shows a different pair and states no model year in its text. Both sources are kept on file; the year-specific brochure is the one this record uses.
Length, height, tank sizes, and the room labels come from the same brochure, read again on 2026-09-26. It describes its weights as the average of a standard build and notes that its heights exclude a second air conditioner. GVWR, sleeping capacity, and slide count in the table come from RVUSA's 2026 spec guide.