17N253321 2026 Newmar Mountain Aire 4118 HD 1080p

Transwest Truck Trailer RV
Lance Ortega (208)290-5750

- - - - - - 2026 Newmar Mountain Aire 4118 - - - - - - - -

The 2026 Newmar Mountain Aire 4118 is a flagship luxury diesel motorhome designed for refined long-distance travel and full-time comfort. Built on the Spartan K3 tag-axle chassis, the Mountain Aire delivers exceptional ride quality, stability, and confidence on the road.
Powering the 4118 is a 12.0-liter Cummins X12 diesel engine producing 525 horsepower and 1,850 lb-ft of torque, paired with an Allison 4000 Series automatic transmission. This powertrain provides smooth acceleration, confident hill-climbing capability, and a composed driving experience in all conditions.
Inside, the Mountain Aire 4118 features a spacious bath-and-a-half floorplan with opposing living-area slides that create an open, residential-style interior. Handcrafted hardwood cabinetry, premium materials, and refined finishes define the living space, making this coach well suited for extended travel or full-time ownership.


2026 Newmar Mountain Aire 4118

– Specifications
Chassis and Powertrain
Spartan K3 tag-axle chassis
Cummins X12 diesel engine
12.0-liter displacement
525 horsepower
1,850 lb-ft of torque
Allison 4000 automatic transmission
Independent front suspension
Air disc brakes

-Dimensions (Approximate)
Overall length: 41 ft 11 in
Exterior width: 8 ft 5 in
Exterior height: approximately 12 ft 11 in
Interior ceiling height: approximately 84 in

-Weight Ratings
(Typical for K3 Tag-Axle Configuration)
GVWR: approximately mid-54,000 lb range
GCWR: determined by final chassis certification
Hitch rating: up to 15,000 lbs

-Tank Capacities (Approximate)
Fuel capacity: approximately 150 gallons
Fresh water capacity: approximately 105 gallons
Gray water capacity: approximately 75 gallons
Black water capacity: approximately 60 gallons
LP gas capacity: approximately 40 lbs

-Construction
STAR Foundation chassis integration
One-piece molded fiberglass roof
Aluminum-framed, foam-insulated sidewalls
Full-paint exterior finish
Flush-mounted dual-pane windows

-Interior and Living
Bath-and-a-half floorplan
Heated tile flooring
Handcrafted hardwood cabinetry
Power theater seating
Residential-style furnishings
Solid-surface countertops
LED lighting throughout

-Kitchen
Residential refrigerator
Induction cooktop
Convection microwave
Optional dishwasher
Large pantry and storage capacity

-Bedroom and Bath
King-size bed
Rear master bath with residential-style shower
Mid-coach half bath
Large rear wardrobe with washer and dryer prep

-Comfort and Technology
Whisper Quiet Climate Control system
Multi-zone air conditioning
Hydronic heating system interior heat & hot water
Digital coach control system
Multiple high-definition televisions
Premium audio system


Lance Ortega's Facebook Page
www.facebook.com/webuyrvs

Lance Ortega's Instagram
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Transwest website
www.transwestrv.com


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