01 What makes it unique
The 30G carries the biggest cargo box Grand Design builds into a Momentum, fifth wheel or trailer: twenty feet seven inches, three and a half feet longer than the flagship 392M's seventeen-foot garage, in a trailer that weighs 9,139 pounds dry. That is the whole argument for this plan. It sleeps seven on two slides, gets a king bed as standard where most of the roster gets a 60x80 queen, and runs 28,500 BTU of air conditioning. The G-Class trailer standards are all here: a full-sized rear ramp door, no wheel wells in the garage, 2,500-pound chassis-anchored tie-downs, rear-ramp loading lights and the 30-gallon fuel station with interior and exterior gauges.
The published weights give 13,000 pounds of GVWR against 9,139 dry, so payload is 3,861 pounds, with a 1,425-pound dry tongue. Read the garage figure and the payload figure together: twenty feet of floor will happily accept more than 3,861 pounds of machinery, and the trailer will not tell you when you have passed the line. The tongue is the other constraint — at 1,425 pounds dry it is a three-quarter-ton conversation once loaded, not a half-ton one.
02 Full specifications
Dimensions
- Exterior length
- 34 ft 10 in
- Exterior width
- 8 ft 5 in
- Width, slides out
- 11 ft 4 in
- Exterior height
- 12 ft 4 in
- Interior height
- 7 ft 7 in
- Garage / flex length
- 20 ft 7 in
Weights
- Dry / unit base weight (UVW)
- 9,139 lbs
- GVWR (max loaded)
- 13,000 lbs
- Net cargo / payload
- 3,861 lbs
- Dry tongue weight
- 1,425 lbs
Capacities
- Fresh water
- 90 gal
- Grey water
- 78 gal
- Black water
- 39 gal
- LP gas
- 40 lbs · 2 tanks
- Refrigerator
- 8 cu. ft.
Construction
- Sidewalls
- Laminated aluminum framed (R-7)
- Roof
- 5″ radius wood framed (R-40*) · double-insulated roof and front cap
- Ramp door
- Laminated aluminum framed (R-12)
- Front cap
- Fiberglass w/ paint · 48″ LED front cap lighting
- Underbelly
- Heated and enclosed w/ suspended tanks
Running gear
- Hitch
- Bumper pull
- Wheel wells
- None — flat garage floor
- Spare
- Full-sized spare tire and carrier
- Roof access
- Folding roof ladder · walk-on roof
Garage
- Garage / flex length
- 20 ft 7 in
- Garage insulation
- R-30
- Ramp
- Full-sized rear ramp door · rear-ramp loading lights w/ back-up function
- Tie-downs
- 2,500 lb tie-downs anchored into the chassis
- Fuel station
- 30 gal
Galley & systems
- Refrigerator
- 8 cu. ft. 12-volt
- Air conditioning
- 28,500 BTU
- Furnace
- 30,000 BTU
- Water heater
- Tankless
- Solar
- 220W roof-mounted panel · 30 AMP controller
- Shower
- 27 X 36
Sleeping & layout
- Sleeps
- 7
- Slides
- 2
- Awnings
- 1 · 19 ft
- Hitch type
- Bumper pull
- Primary bed
- King Bed
03 The Momentum floorplan family
Momentum is Grand Design's toy-hauler family, and it spans four rosters across both tow types. The full-size Momentum fifth wheel is the flagship — a 101-inch wide-body coach on MORryde independent suspension with disc brakes, carrying a 60-gallon dual fuel station. The Momentum G-Class fifth wheel sits below it on MORryde CRE3000 suspension and a Rotoflex pin box with a 30-gallon fuel station, and the G-Class travel trailer puts that same garage behind a bumper pull. The Momentum MAV is the compact end — the lightest and cheapest way into a Momentum garage, and the one roster with no fuel station at all. The 30G on this page is highlighted; each other profiled plan links to its own page. The full MY2027 catalogue runs to 28 floorplans across the four rosters; eight are profiled in depth here and the rest are catalogued on the line hub with their weights.
| Floorplan | Roster | Type | Length | Garage | Sleeps | Notable |
|---|---|---|---|---|---|---|
| 344M | Momentum | 5W | 39′ 11″ | 11 ft | 6 | Entry Momentum — lowest GVWR of the ten, tightest payload |
| 392M | Momentum | 5W | 45′ 11″ | 17 ft | 9 | Sleeps nine, longest fifth-wheel garage in the family |
| 320G | Momentum G-Class | 5W | 36′ 3″ | 11 ft | 6 | Entry G-Class fifth wheel — lowest GVWR of the six |
| 394G | Momentum G-Class | 5W | 44′ 11″ | 15 ft* | 7 | Top G-Class GVWR, biggest G-Class payload, triple awning |
| 21G | Momentum G-Class | TT | 26′ 11″ | 14 ft* | 6 | Entry G-Class trailer — only single-slide, lowest GVWR |
| 30G | Momentum G-Class | TT | 34′ 10″ | 20 ft 7 in | 7 | Longest garage in the whole Momentum family |
| 17MAV | Momentum MAV | TT | 22′ 11″ | 11 ft 6 in | 2 | Lightest and cheapest Momentum built |
| 28MAV | Momentum MAV | TT | 33′ 11″ | 10 ft 4 in | 6 | Top of the MAV range — the only MAV with a slide-out |
The Momentum G-Class travel trailer brings the G-Class garage to a bumper-pull, for buyers who want a real toy hauler without an in-bed hitch. Laminated aluminum walls, a full-sized rear ramp door, a flat no-wheel-well garage floor and a 30-gallon fuel station are standard across the roster. Tongue weights are factory dry figures — weigh the loaded trailer and confirm against your vehicle's door-jamb placard. Additional G-Class travel-trailer floorplans are catalogued on the line hub.
04 What owners & reviewers report
Longest garage of all 28 Momentum floorplans
Twenty feet seven inches — longer than any G-Class or full-size Momentum fifth wheel, including the 17-foot 392M.
King bed standard
Where most of the G-Class trailer roster publishes a 60x80 queen, this plan publishes a king.
The garage can outrun the payload
3,861 pounds of payload under twenty feet seven inches of garage floor. The space will take more than the axles will — weigh it.
1,425-pound dry tongue
Loaded to 13,000 pounds with cargo forward of the axles, expect materially more. Confirm against the tow vehicle's placard.
05 How it compares
A 13,250-pound-GVWR travel-trailer toy hauler with a published 4,610-pound cargo capacity — more payload, but Heartland publishes no garage length at all.
Eight feet shorter, one slide, and a fourteen-foot garage — six thousand dollars less.
A 16,400-pound-GVWR fifth wheel for about forty-seven thousand dollars more — but the garage drops to eleven feet.