01 What makes it unique
Coachmen lists the 2025 Brookstone 398MBL at 13,155 lb dry, a GVWR of 15,500 lb, a net carrying capacity of 2,345 lb and a pin weight of 2,239 lb. Its dry weight plus its carrying capacity comes to exactly its GVWR.
It is 42' 2" long and 13' 2" high. Coachmen prints its tanks as 60 gal fresh, 85 gal grey, 45 gal black.
Among the 5 Brookstone floorplans Coachmen’s 2025 Brookstone brochure lists with a published dry weight, it is number 5 from the lightest, in a range from 11,472 lb (Brookstone 290RL) to 13,155 lb (Brookstone 398MBL). Every figure in that comparison is Coachmen’s, for the same model year.
Every number on this page was read on 5 Nov 2026 from Coachmen’s 2025 Brookstone brochure, the maker’s own dated document for model year 2025.
How the 398MBL differs from the other four Brookstone floorplans. Most distinctive first. How these ranks are worked out.
- Dry weight, 13,155 lb: heaviest of five; next is the 374RK (13,020 lb).
- Cargo capacity, 2,345 lb: third-smallest of five, between the 370RLLO (2,270 lb) and the 374RK (2,480 lb).
- Pin weight, 2,239 lb: third-lightest of five, between the 374RK (2,212 lb) and the 290RL (2,466 lb).
- GVWR, 15,500 lb: highest of five, level with the 374RK; next are the 344FL and 370RLLO (15,000 lb).
- Grey tank, 85 gal: smallest of five, level with the 370RLLO; next are the 290RL, 344FL and 374RK (90 gal).
- Cargo capacity as a share of GVWR, 15.1%: shared with the 370RLLO; of five, one smaller and two larger, nearest the 344FL (14.7%) and the 374RK (16%).
- Pin weight as a share of dry weight, 17%: shared with the 374RK; of five, one smaller and two larger, nearest the 370RLLO (16.8%) and the 290RL (21.5%).
Next to the 374RK, the nearest lighter floorplan by dry weight, the 398MBL is 135 lb heavier by dry weight, has 135 lb less cargo capacity, has a pin weight 27 lb heavier and has a grey tank 5 gal smaller; the two publish the same GVWR, length, exterior height, fresh tank and black tank.
02 Full specifications
Dimensions
- Exterior length
- 42' 2"
- Exterior height
- 13' 2"
- Exterior width
- Not published by Coachmen
- Interior height
- Printed in the brochure, not transcribed here
Weights
- Dry / unit base weight (UVW)
- 13,155 lb
- GVWR (max loaded)
- 15,500 lb
- Net cargo / payload (CCC)
- 2,345 lb
- Hitch / pin weight
- 2,239 lb
Capacities
- Fresh water
- 60 gal
- Grey water
- 85 gal
- Black water
- 45 gal
Running gear
- Hitch type
- Fifth wheel (pin box)
- Tire size
- 16" G
Sleeping & layout
- Sleeps
- Not published by Coachmen
- Awning
- 20'
- Wheel size
- 16"
- Picture caption prints
- 42' 2", 13,020 lb (UVW) — conflict with the table, stated not resolved
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.
Drawn to scale
Weight budget
Size (no width published)
Holding tanks
Axles, wheels and nose shape are schematic; not a floorplan. Data: dataset.
Towing it
Check your vehicle. Enter the ratings from your owner’s manual and the door-pillar placard.
Compares your figures with this page’s published GVWR (15,500 lb) and the upper loaded pin estimate (3,875 lb, a rule of thumb). Your vehicle’s placard and the trailer’s own weight label govern.
Loaded range: 15–25% of GVWR on the pin, a rule of thumb, not a measurement of this unit. No truck ratings or hitch classes (why; NHTSA, DOT HS 809 433).
03 The Brookstone floorplan family
Coachmen’s 2025 Brookstone brochure lists 6 Brookstone floorplans; every one with a printed weight has a page here.
| Floorplan | Nominal | Sleeps | Notable |
|---|---|---|---|
| Brookstone 290RL | 36' 4\" | — | Profiled |
| Brookstone 370RLLO | 41' 4\" | — | Profiled |
| Brookstone 344FL | 42' 2\" | — | Profiled |
| Brookstone 374RK | 42' 2\" | — | Profiled |
| Brookstone 398MBL | 42' 2\" | — | Profiled |
| Brookstone 318RLL | 42' 2\" | — | Catalogued · Coachmen prints its weights as TBD |
Coachmen’s 2025 Brookstone brochure lists 6 Brookstone floorplans. Every one with a printed weight has a page here.
04 Notes on this floorplan
What Coachmen does not publish for the Brookstone 398MBL
Coachmen prints no sleeping capacity for this model, so none is given. Nothing is filled from a sibling model, 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). Those figures come from the trailer itself and govern the towing decision.
05 How it compares
13,020 lb dry and 15,500 lb GVWR, against this model’s 13,155 lb and 15,500 lb.
06 Loading it for a trip
A full 60-gallon fresh tank is about 498 lb of water (water counts as cargo: 49 CFR 571.120 S10.4.2), 21% of the Brookstone 398MBL’s 2,345 lb cargo capacity, leaving 1,847 lb. Across 5 Brookstone floorplans the water share runs 16% to 23%, and 2 give up more than this one. Nearest on that share: Brookstone 374RK at 20% and Brookstone 370RLLO at 22%. Your own unit’s figure is on the label inside its entry door (49 CFR 571.120 S10.4.3).
07 Where this floorplan sits
Closest sibling: the Brookstone 374RK, nearest on the published figures. It differs on 4 of the 8 fields both publish (this plan first): dry weight 13,155 lb vs 13,020 lb; cargo capacity 2,345 lb vs 2,480 lb; hitch weight 2,239 lb vs 2,212 lb; grey tank 85 gal vs 90 gal. They match on length, GVWR, fresh tank and black tank.
| Brookstone plans | This plan | Position, low to high | Range |
|---|---|---|---|
| GVWR (lb) | 15,500 | 4–5 of 5 | 14,500–15,500 |
| Dry weight (lb) | 13,155 | 5 of 5 | 11,472–13,155 |
| Cargo capacity (lb) | 2,345 | 3 of 5 | 2,211–3,028 |
| Hitch weight (lb) | 2,239 | 3 of 5 | 2,144–2,823 |
| Length | 42 ft 2 in | 3–5 of 5 | 36 ft 4 in–42 ft 2 in |
| Grey tank (gal) | 85 | 1–2 of 5 | 85–90 |
| Black tank (gal) | 45 | 1–4 of 5 | 45–90 |
Either side of it by GVWR: Brookstone 374RK matches it at 15,500 lb GVWR.
| Nearest Brookstone siblings | Length | Sleeps | Dry (lb) | GVWR (lb) | CCC (lb) | Hitch (lb) | Fresh (gal) |
|---|---|---|---|---|---|---|---|
| Brookstone 398MBL | 42 ft 2 in | — | 13,155 | 15,500 | 2,345 | 2,239 | 60 |
| Brookstone 374RK | 42 ft 2 in | — | 13,020 | 15,500 | 2,480 | 2,212 | 60 |
| Brookstone 370RLLO | 41 ft 4 in | — | 12,730 | 15,000 | 2,270 | 2,144 | 60 |
| Brookstone 290RL | 36 ft 4 in | — | 11,472 | 14,500 | 3,028 | 2,466 | 60 |
| Brookstone 344FL | 42 ft 2 in | — | 12,789 | 15,000 | 2,211 | 2,823 | 60 |
All 5 Brookstone floorplans: Brookstone line hub.
| Other lines, nearest by GVWR | GVWR (lb) | Dry (lb) | Sleeps | Length |
|---|---|---|---|---|
| Brookstone 398MBL | 15,500 | 13,155 | — | 42 ft 2 in |
| Chaparral 367BH | 15,500 | 12,328 | — | 42 ft 6 in |
| ElkRidge 37RED | 15,500 | 11,848 | 6 | 41 ft 7 in |
| Mesa Ridge 371MBH | 15,500 | 12,665 | — | 42 ft 5 in |
| Shasta Phoenix 367BH | 15,500 | 12,328 | — | 42 ft 6 in |
| Sandpiper 3710HBFB | 15,500 | 12,649 | 7 | 42 ft 9 in |
| Sierra 3710HBFB | 15,500 | 12,649 | — | 42 ft 9 in |
08 Common questions about the Brookstone 398MBL
How much does the Brookstone 398MBL weigh?
13,155 lb dry; 15,500 lb GVWR, the most it may weigh loaded.
How much can the Brookstone 398MBL carry?
2,345 lb, 15% of its GVWR (median across 334 fifth wheels here: 18%). A full fresh tank uses 498 lb of it.
What is the pin weight of the Brookstone 398MBL?
2,239 lb as published, 17% of the dry weight (median across 540 fifth wheels here: 19%).
What size tow vehicle does the Brookstone 398MBL need?
A tow rating of at least 15,500 lb, plus payload for the loaded pin weight, passengers and cargo.
What are the tank capacities on the Brookstone 398MBL?
Fresh 60, grey 85, black 45 gallons. Off hookups, fresh water runs out first.
How long is the Brookstone 398MBL?
42' 2" overall, tongue or pin box included.
From the figures above.
09 What this page publishes, and what it does not
10 of the 18 fields this catalogue tracks are published for the Brookstone 398MBL. Not published: exterior width, interior height, sleeps, slide count, axle count, refrigerator, air conditioning, tire size (a description is published, a size is not).
Sourcing rules: methodology.
10 Manuals & documents
Sources: forestriverinc.com, library.rvusa.com (linked below); the full source note is at the foot of the page.