Newmar Mountain Aire 4589

Name: Newmar Mountain Aire 4589
Brand: Newmar

Class Abuilt 2020–22Better build tierScarce on the used market

WHAT ONE COSTS

$406,400est. used (2022, 4 yr old)

Sticker was $677,851 in 2022. Out of production since 2022, so the used market is the only way to buy one. Estimate assumes a 2022 unit.

THE SPECS

Length44.8 ft

Height (incl. A/C)13.2 ft

Width8.5 ft

Interior height6.9 ft

GVWR54,000 lb

Dry weight45,200 lb

Sleeps5

Fresh water105 gal

Grey water80 gal

Black water60 gal

Fuel150 gal

GeneratorCummins Onan 12.5 kW diesel

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

WHERE PEOPLE SLEEP

1× king 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

2020Introduced
2023Dropped

FINDING ONE

Scarce: months of watching; be ready to fly and drive it home. Estimated from build volume and production span, not a count of live listings.

OUR TAKE

Early-2020s 45-foot plan from the era when Mountain Aire ran six floorplans.

OTHER MOUNTAIN AIRE FLOORPLANS

3823 · 54,000 lb · sleeps 5 3825 · 54,000 lb · sleeps 4 4002 · 54,000 lb · sleeps 5 4018 · 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 the whole line →

Find one for sale

Live listings for the 4589 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 4589 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 manufacturer spec sheets, retrieved 2026-07.