Tiffin Phaeton 40IH vs Newmar King Aire 4531

Tiffin · Class A

The difference that matters

Scale separates them. The King Aire 4531 is Newmar's flagship: 44.9 ft on a Spartan K3 tag-axle chassis with a 605 hp Cummins X15, a 54,000 lb GVWR and a 20,000 lb hitch. The Phaeton 40IH is 41.3 ft with a 450 hp Cummins L9, a 40,000 lb GVWR and a 10,000 lb tow rating.

The King Aire's house system is built around 2,560 Ah of lithium and a 12.5 kW Onan, with a spa-style bath, a midship half bath and a built-in washer and dryer. It sleeps five and has four slides. Its cargo capacity is 4,100 lb.

The Phaeton also has four slides and sleeps six. It carries 600 W of solar against the King Aire's 10 W, a 3,000 W inverter, a 10.0 kW diesel generator, hydronic heat with electric appliances and six AGM batteries, with lithium optional. Its gray tank holds 100 gal against 80.

Tiffin Phaeton 40IH: A family of up to six who want solar and hydronic heat in a 41 ft diesel pusher.
Newmar King Aire 4531: Flagship tag-axle coach buyers, as couples, who want a huge lithium bank, a spa bath and a built-in washer.

Weights

2027 maker figures

GVWR: 40,000 lb
Dry weight (UVW): not published
Occupant + cargo (OCCC): not published
Towing capacity: 10,000 lb

Weights

2027 maker figures

GVWR: 54,000 lb
Dry weight (UVW): 49,900 lb
Occupant + cargo (OCCC): 4,100 lb
Towing capacity: 20,000 lb

4,100 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

	Tiffin Phaeton 40IH	Newmar King Aire 4531
Dry weight (UVW)	—	49,900 lb
GVWR	40,000 lb	54,000 lb
Cargo capacity (CCC / OCCC)	—	4,100 lb
GVWR minus dry weight	—	4,100 lb
Towing capacity	10,000 lb	20,000 lb
Exterior length	41.3 ft	44.9 ft
Exterior height	13.3 ft	13.3 ft
Sleeps	6	5
Slide-outs	4	4
Fresh water	100 gal	105 gal
Gray water	100 gal	80 gal
Black water	55 gal	60 gal
Factory solar	600 W	10 W
House battery	(6) 6V 210Ah extended-cycle AGM (lithium optional)	4 house batteries, 2560 Ah total (standard)
Generator	10.0 kW Onan Quiet Diesel	Cummins Onan 12.5 kW
Chassis	Tiffin PowerGlide XC raised-rail rear-engine diesel	Spartan
Engine	Cummins L9 450 HP	Cummins 15.0L, 605 hp; Allison 6-speed
Fuel	Diesel	Diesel

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

To scale

051015202530354045 ft

Tiffin Phaeton 40IH · 41.3 ft long · 13′4″ tall
Newmar King Aire 4531 · 44.9 ft long · 13′4″ 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.

Tiffin Phaeton 40IH

Full spec sheet, sources →

Newmar King Aire 4531

Full spec sheet, sources →