01 What makes it unique
The 28MAV is where the MAV roster ends: thirty-three feet eleven inches, sleeping six, and the only MAV of the five that Grand Design gives a slide-out. It keeps the MAV build — the 24-inch DoveTail loading ramp, the garage pull-down screen, no wheel wells in the garage, R-9 walls, an R-40 TPO roof with a limited lifetime warranty and a heated enclosed underbelly with suspended tanks — and adds an on-demand water heater. At $60,211 it is the most expensive MAV and still twelve thousand dollars under the entry G-Class trailer.
The trade against the rest of the roster is payload. Grand Design publishes 11,000 pounds of GVWR against 8,300 dry, leaving 2,700 pounds — the tightest in the MAV range and well under half the 17MAV's 4,408, on a trailer that is eleven feet longer. The garage is also the shortest of the five at ten feet four inches. What you buy here is living space and sleeping capacity, not cargo capacity. The 1,200-pound dry tongue is the highest in the roster. And as with every MAV, there is no fuel station: the field is published as N/A and no fuel figure appears on this page.
02 Full specifications
Dimensions
- Exterior length
- 33 ft 11 in
- Exterior width
- 8 ft 4 in
- Width, slides out
- 11 ft 6 in
- Exterior height
- 12 ft 2 in
- Interior height
- 7 ft*
- Garage / flex length
- 10 ft 4 in
Weights
- Dry / unit base weight (UVW)
- 8,300 lbs
- GVWR (max loaded)
- 11,000 lbs
- Net cargo / payload
- 2,700 lbs
- Dry tongue weight
- 1,200 lbs
Capacities
- Fresh water
- 90 gal
- Grey water
- 74 gal
- Black water
- 37 gal
- LP gas
- 40 lbs · 2 tanks
- Refrigerator
- 8 cu. ft.
Construction
- Sidewalls
- Insulated (R-9)
- Roof
- TPO membrane w/ limited lifetime warranty · R-40 · walk-on
- Main floor
- Insulated (R-11)
- Slide rooms
- Roof and end wall insulation (R-9)
- Underbelly
- Heated and enclosed w/ suspended tanks
Running gear
- Hitch
- Bumper pull
- Wheel wells
- None in garage — flat floor
- Spare
- Undermount
- Roof access
- Walk-on roof
Garage
- Garage / flex length
- 10 ft 4 in
- Garage insulation
- R-25
- Ramp
- 24″ DoveTail loading ramp · garage pull-down screen
- Tie-downs
- 2,500 lb tie-downs anchored into the chassis
Galley & systems
- Refrigerator
- 8 cu. ft. 12-volt
- Air conditioning
- 15,000 BTU
- Furnace
- 30,000 BTU
- Water heater
- On Demand
- Solar
- 200W solar prep (wiring, not a panel)* · 30 AMP controller · 2,000W inverter prep
- Shower
- 27″ x 36″
Sleeping & layout
- Sleeps
- 6
- Slides
- 1
- Awnings
- 1 · 19 ft
- Hitch type
- Bumper pull
- Primary bed
- 60″ x 80″ Queen 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 28MAV 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 MAV is the compact end of the family — the lightest, cheapest way into a Momentum garage, on a single-axle-to-tandem bumper-pull with a 24-inch DoveTail loading ramp. It is the one Momentum roster that does NOT carry a fuel station: Grand Design prints N/A into the Fuel Capacity field on all five MAV plans and omits the fuel bullet from the MAV feature list, so no fuel figure is shown here. Additional MAV floorplans are catalogued on the line hub.
04 What owners & reviewers report
The only MAV with a slide-out
One slide where the other four MAV plans publish none.
Tightest payload in the MAV range
2,700 pounds — against 4,408 on the much smaller 17MAV. Length and sleeping capacity cost cargo here.
Shortest MAV garage
Ten feet four inches, the smallest of the five, in the longest MAV body.
Interior height published without a unit
The factory prints a bare 7 for interior height where all four sibling MAV plans print 7 feet. Feet is the only consistent reading, but it is our reading, so it is flagged.
05 How it compares
Eleven feet shorter and thirteen thousand less, sleeps two — but 1,708 more pounds of payload and a longer garage.
Seven feet shorter but a 30-gallon fuel station, a fourteen-foot garage and 1,020 more pounds of payload, for about fourteen thousand more.
A 11,700-pound-GVWR trailer toy hauler sleeping four, with a published 4,255-pound cargo capacity and a mandatory 30-gallon fuel tank.