01 What makes it unique
Keystone publishes three weights for the Carbon 363: a shipping weight of 12,500 lb, a carrying capacity of 4,175 lb and a hitch weight of 2,720 lb. Those are Keystone’s own terms, and this page keeps them. Keystone does not call the first figure dry or unloaded weight, does not say the hitch figure is measured dry, and publishes no GVWR for any Carbon floorplan, so none of the three is renamed here and no loaded rating is worked out from them. The trailer’s own federal weight label, inside the door, is the document that carries its UVW, cargo capacity and GVWR.
Tank capacities are 94 gal fresh, 88 gal gray and 44 gal waste, as Keystone lists them. Fresh water weighs about 8.3 lb per US gallon, so a full fresh tank is roughly 780 lb on the road before anything else is loaded. The tire size Keystone lists is ST235/80R16G; a fifth wheel puts its pin load into the truck bed, so it counts against the truck’s payload rather than its tow rating.
Against the 6 Carbon floorplans profiled here, this one is the 4th by Keystone’s shipping weight, in a range from 11,085 lb (310) to 15,370 lb (420). Every figure in that comparison comes from the same Keystone page type for the same model year, so the comparison inside the series is like for like.
Every number on this page was read on 5 Nov 2026 from Keystone’s own floorplan page for the Carbon 363. That page carries no model year, so the year comes from the roster page that links it, which lists the Carbon floorplans under the heading “2027 Floorplans” (this floorplan sits beyond the cards the page renders, and the heading’s own count equals the roster’s full list of floorplan pages). Keystone notes that its website reflects the most recent production run and that features and specifications change during the year.
How the 363 differs from the other five Carbon floorplans. Most distinctive first. How these ranks are worked out.
- Carrying capacity (Keystone’s term), 4,175 lb: second-smallest of six, between the 368 (3,064 lb) and the 330 (4,360 lb).
- Shipping weight (Keystone’s term), 12,500 lb: third-heaviest of six, between the 330 (12,405 lb) and the 368 (13,636 lb).
- Length, 40 ft 7 in: shared with the 368; of six, three shorter and one longer, nearest the 361LT (39 ft 11 in) and the 420 (44 ft 11 in).
- Sleeping capacity, 6: smallest of six, level with the 310 and 330; next are the 361LT, 368 and 420 (7).
- Hitch weight as Keystone lists it, 2,720 lb: shared with the 368; of six, two lighter and two heavier, nearest the 361LT (2,605 lb) and the 330 (2,765 lb).
- Hitch weight as a share of shipping weight, 21.8%: shared with the 420; of six, two smaller and two larger, nearest the 310 (21.5%) and the 361LT (22%).
Next to the 330, the nearest lighter floorplan by shipping weight, the 363 is 95 lb heavier by shipping weight, has 185 lb less carrying capacity, has a hitch weight 45 lb lighter and is 4 ft 8 in longer; the two publish the same exterior height, fresh tank, grey tank and sleeping capacity.
Next to the 368, the nearest heavier floorplan by shipping weight, the 363 is 1,136 lb lighter by shipping weight, has 1,111 lb more carrying capacity and sleeps one fewer; the two publish the same hitch weight, length, exterior height, fresh tank and grey tank.
02 Full specifications
Dimensions
- Exterior length
- 40' 7"
- Exterior height
- 13' 3"
- Exterior width
- Not published by Keystone
Weights
- Dry / unit base weight (UVW)
- Not published by Keystone
- GVWR (max loaded)
- Not published by Keystone
- Shipping weight (Keystone’s term)
- 12,500 lb
- Carrying capacity (Keystone’s term)
- 4,175 lb
- Hitch weight, as Keystone lists it
- 2,720 lb
Capacities
- Fresh water
- 94 gal
- Gray water
- 88 gal
- Waste water
- 44 gal
Running gear
- Hitch type
- Fifth wheel (pin box)
- Tire size
- ST235/80R16G
Sleeping & layout
- Sleeps
- 6
- Propane
- 60 lb
- Refrigerator
- 16 cu ft
How these published figures sit against the rest of the catalogue: fifth wheel pin weight and payload; fresh, grey and black tank sizes; camper trailer size chart.
Towing it
Can’t check: Keystone publishes no GVWR. A tow check needs the GVWR, the most the trailer may weigh loaded, and Keystone prints none for this floorplan, so this site does not work one out. Read the GVWR on the trailer’s own federal weight label and hold it against your tow vehicle’s ratings.
03 The Carbon floorplan family
Keystone lists 6 Carbon floorplans for 2027. 6 have a complete Keystone figure set and no existing page here, and are profiled, from 11,085 lb to 15,370 lb shipping weight; the others are catalogued on this page with the reason against each. Keystone publishes shipping weight, carrying capacity and hitch weight for these trailers, and no GVWR.
| Floorplan | Nominal | Sleeps | Notable |
|---|---|---|---|
| 310 | 35' 11" | 6 | Profiled |
| 361LT | 39' 11" | 7 | Profiled |
| 330 | 35' 11" | 6 | Profiled |
| 363 | 40' 7" | 6 | Profiled |
| 368 | 40' 7" | 7 | Profiled |
| 420 | 44' 11" | 7 | Profiled |
Keystone lists 6 Carbon floorplans for 2027. 6 are profiled here; the rest are catalogued with the reason against each.
04 Notes on this floorplan
What Keystone does not publish for the Carbon
No GVWR, no unloaded (dry) weight under that name, no dry hitch weight and no exterior width appear on Keystone’s floorplan pages for this series, so those rows read as not published. Nothing is filled from a sibling floorplan, a different model year or a dealer listing.
Read the label on the trailer
Federal rules put a load-carrying label inside every RV trailer: its unloaded weight with full propane, its cargo carrying capacity and its GVWR (49 CFR 571.110 and 571.120). On a Carbon those figures come from the trailer, not from this page, and they govern the towing decision.
05 How it compares
12,405 lb shipping weight against this plan’s 12,500 lb (Keystone’s figures, same series, same model year).
13,636 lb shipping weight and 3,064 lb carrying capacity, against this plan’s 12,500 lb and 4,175 lb.
07 Where this floorplan sits
Closest sibling: the Carbon 330, nearest on the published figures. It differs on 2 of the 5 fields both publish (this plan first): length 40 ft 7 in vs 35 ft 11 in; hitch weight 2,720 lb vs 2,765 lb. They match on sleeps, fresh tank and grey tank.
| Carbon plans | This plan | Position, low to high | Range |
|---|---|---|---|
| Hitch weight (lb) | 2,720 | 3–4 of 6 | 2,380–3,345 |
| Length | 40 ft 7 in | 4–5 of 6 | 35 ft 11 in–44 ft 11 in |
| Sleeps | 6 | 1–3 of 6 | 6–7 |
| Nearest Carbon siblings | Length | Sleeps | Dry (lb) | GVWR (lb) | CCC (lb) | Hitch (lb) | Fresh (gal) |
|---|---|---|---|---|---|---|---|
| Carbon 363 | 40 ft 7 in | 6 | — | — | — | 2,720 | 94 |
| Carbon 330 | 35 ft 11 in | 6 | — | — | — | 2,765 | 94 |
| Carbon 368 | 40 ft 7 in | 7 | — | — | — | 2,720 | 94 |
| Carbon 361LT | 39 ft 11 in | 7 | — | — | — | 2,605 | 94 |
| Carbon 310 | 35 ft 11 in | 6 | — | — | — | 2,380 | 94 |
| Carbon 420 | 44 ft 11 in | 7 | — | — | — | 3,345 | 94 |
All 6 Carbon floorplans: Carbon line hub.
08 Common questions about the 363
What is the pin weight of the 363?
2,720 lb as published.
How many people does the 363 sleep?
It is rated to sleep 6. 3 of the 6 Carbon floorplans that publish a count sleep more.
What are the tank capacities on the 363?
Fresh 94, grey 88 gallons.
How long is the 363?
40' 7" overall, tongue or pin box included.
From the figures above.
09 What this page publishes, and what it does not
8 of the 18 fields this catalogue tracks are published for the 363. Not published: dry weight, GVWR, cargo capacity (CCC), exterior width, interior height, black tank, slide count, axle count, awning, air conditioning.
Sourcing rules: methodology.
10 Manuals & documents
Sources: keystonerv.com (linked below); the full source note is at the foot of the page.
11 NHTSA safety record
NHTSA holds 12 recall campaigns and 9 owner complaints (model years 2005 on) against the Carbon line (a recall and a complaint are not the same thing).
Too few reports to show a pattern. 9 complaints have been filed on this line — not enough to say what fails most often. They cover structure, seats, fuel system, gasoline, suspension and wheels.
Recall coverage here is not complete, and complaints are owners’ unverified reports (how this record is built). Check a specific VIN at NHTSA before you buy. Full tables are on the Carbon line page.