Newmar King Aire 4578

Name: Newmar King Aire 4578
Brand: Newmar

Class Abuilt 2022–22Better build tierScarce on the used market

WHAT ONE COSTS

$822,700est. used (2022, 4 yr old)

Sticker was $1,372,368 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

Length44.9 ft

Height (incl. A/C)13.3 ft

Width8.5 ft

Interior height6.9 ft

GVWR54,000 lb

Dry weight49,200 lb

Cargo capacity4,800 lb

Sleeps4

Slide-outs3

Fresh water105 gal

Grey water80 gal

Black water60 gal

Air conditioning45,000 BTU

Fuel200 gal

Engine / chassisCummins X15 605 hp diesel pusher

GeneratorCummins Onan 12.5 kW diesel

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

WHERE PEOPLE SLEEP

1× Rear king bed(Permanent)72×80
1× Hide-a-bed sofa(Convertible)—

HOW IT'S BUILT: 4/5

WallsLaminated fiberglass

FrameSteel

RoofWalk-on

UnderbellyEnclosed

Newmar (Better tier): Newmar

YEAR BY YEAR: WHAT CHANGED

2022Introduced
2023Discontinued

FINDING ONE

Scarce: months of watching; be ready to fly and drive it home. Why: only one model year; priced at the top of its maker’s range. Estimated from build volume and production span, not a count of live listings.

OUR TAKE

One-year-only 2022 plan, shared with the Essex that year.

OTHER KING AIRE FLOORPLANS

4501 · 54,000 lb · sleeps 4 4503 · 54,000 lb · sleeps 4 4507 · 54,000 lb · sleeps 4 4513 · 54,000 lb · sleeps 4 4518 · 54,000 lb · sleeps 4 4519 · 54,000 lb · sleeps 4 4521 · 54,000 lb · sleeps 5 4531 · 54,000 lb · sleeps 5 4533 · 54,000 lb · sleeps 4 4534 · 54,000 lb · sleeps 4 4536 · 54,000 lb · sleeps 4 4537 · 54,000 lb · sleeps 4 4540 · 54,000 lb · sleeps 7 4546 · 54,000 lb · sleeps 4 the whole line →

Find one for sale

Live listings for the 4578 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 King Aire line ↗

Is the 4578 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.