Newmar Mountain Aire 4018

Name: Newmar Mountain Aire 4018
Brand: Newmar

Class Abuilt 2014–19Better build tierPatient search on the used market

WHAT ONE COSTS

$315,600est. used (2019, 7 yr old)

Sticker was $497,401 in 2014. Out of production since 2019, so the used market is the only way to buy one. Estimate assumes a 2019 unit.

THE SPECS

Length40.8 ft

Height (incl. A/C)13.2 ft

Width8.5 ft

Interior height6.9 ft

GVWR54,000 lb

Dry weight43,500 lb

Sleeps5

Fresh water105 gal

Grey water65 gal

Black water45 gal

Fuel150 gal

A missing row means the maker never published that figure: unknown, not zero.

WHERE PEOPLE SLEEP

1× master bedroom bed(Permanent)—
1× convertible dinette(Convertible)—
1× sofa sleeper(Convertible)—

HOW IT'S BUILT: 4/5

WallsLaminated fiberglass

FrameSteel

RoofWalk-on

UnderbellyEnclosed

Newmar (Better tier): Newmar Mountain Aire

YEAR BY YEAR: WHAT CHANGED

YEARS	GVWR	DRY	MSRP
2014–15	44,600 lb	36,400 lb	$497,401
2016–19	54,000 lb	43,500 lb	$497,401

2014Introduced at 40'9", 44,600 lb GVWR with the 450 hp Cummins ISL
2017Moved to the 54,000 lb Spartan K2 tag chassis with the 500 hp ISX
2020Dropped

FINDING ONE

Patient search: weeks of watching, and probably some travel. Estimated from build volume and production span, not a count of live listings.

OUR TAKE

Six model years - the 40-foot Mountain Aire that survived the jump from the 450 hp ISL to the 500 hp ISX.

OTHER MOUNTAIN AIRE FLOORPLANS

3823 · 54,000 lb · sleeps 5 3825 · 54,000 lb · sleeps 4 4002 · 54,000 lb · sleeps 5 4118 · 54,000 lb · sleeps 5 4360 · 44,600 lb · sleeps 5 4361 · 44,600 lb · sleeps 5 4364 · 44,600 lb · sleeps 5 4369 · 44,600 lb · sleeps 5 4372 · 44,600 lb · sleeps 5 4501 · 53,000 lb · sleeps 5 4503 · 53,000 lb · sleeps 5 4513 · 54,000 lb · sleeps 5 4519 · 54,000 lb · sleeps 5 4521 · 54,000 lb · sleeps 5 the whole line →

Find one for sale

Live listings for the 4018 on the big marketplaces. Each search opens pre-filled with this exact floorplan:

RV Trader ↗Camping World ↗FB Marketplace ↗Google ↗

Inventory varies by site and day. Slim pickings? search the whole Mountain Aire line ↗

Is the 4018 your #1, or just a spec sheet?

These are the facts. Whether it beats the other six thousand rigs for you depends on what you care about. Set your priorities as sliders, switch on your hard limits, and watch the whole market re-rank around them. Every exclusion explained, every margin shown.

See where it ranks for you →

Data compiled from dealer and aggregator listings, retrieved 2026-07.