Keystone Cougar 360MBI vs Grand Design Influence 3503GK

Keystone · Fifth Wheel

The difference that matters

Ten berths against four tells most of the story. The Cougar 360MBI is a mid-bunk plan that sleeps ten at 39.2 ft, 12,499 lb dry with a 2,200 lb pin and 2,501 lb of cargo capacity. The Influence 3503GK is a three-slide couples plan sleeping four, 38.2 ft and 13,700 lb dry with a 2,670 lb pin and an 18,000 lb GVWR.

The Grand Design carries more built-in hardware. It has 330 W of roof solar with a 50 A Bluetooth controller and inverter prep, a 101 in wide-body SuperChassis, MORryde independent suspension, 17.5 in H-rated tires, an R-40 roof, R-11 walls and an R-45 floor. Tanks are larger at 81/106/53 gal against 75/76/38, and it has a 16 cu ft 12 V fridge.

The Cougar has dual-heated holding tanks, electric four-point auto-leveling, two 15K BTU ducted A/C units (one with a heat pump), a fireplace and a 60K tankless water heater.

Keystone Cougar 360MBI: A big family who need ten berths, a bunk area and auto-leveling in a lighter fifth wheel.
Grand Design Influence 3503GK: Living in it for long stretches as a couple, with solar, heavy insulation and large tanks.

Weights

2027 maker figures

Dry weight (UVW): 12,499 lb
GVWR: not published
Pin weight, dry: 2,200 lb
Cargo capacity (CCC): 2,501 lb

Weights

2027 maker figures

Dry weight (UVW): 13,700 lb
GVWR: 18,000 lb
Pin weight, dry: 2,670 lb
Cargo capacity (CCC): not published

4,300 lb between brochure dry weight and GVWR. Water (8.3 lb a gallon), food, gear, propane and dealer-added options all come out of it.

Spec for spec

	Keystone Cougar 360MBI	Grand Design Influence 3503GK
Dry weight (UVW)	12,499 lb	13,700 lb
GVWR	—	18,000 lb
Hitch / pin weight, dry	2,200 lb	2,670 lb
Cargo capacity (CCC / OCCC)	2,501 lb	—
GVWR minus dry weight	—	4,300 lb
Exterior length	39.2 ft	38.2 ft
Exterior height	13.3 ft	13.4 ft
Sleeps	10	4
Slide-outs	—	3
Fresh water	75 gal	81 gal
Gray water	76 gal	106 gal
Black water	38 gal	53 gal
Factory solar	None	330 W

Bold is the lighter or larger figure. A dash means the maker does not publish it.

To scale

051015202530354045 ft

Keystone Cougar 360MBI · 39.2 ft long · 13′4″ tall
Grand Design Influence 3503GK · 38.2 ft long · 13′5″ tall

Drawn to one scale from each camper's listed length and, where the maker publishes it, its exterior height. Outlines are typical for the camper type, not traced from this model. The figure is a 6 ft person. The dashed blue line is 25 ft, the length about 93% of national park campgrounds accept.

Keystone Cougar 360MBI

Full spec sheet, sources and what owners report →

Grand Design Influence 3503GK

Full spec sheet, sources →