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Thor Motor Coach Aria 3901

Class Abuilt 2017– (in production)Mixed build tierCommon on the used market
WHAT ONE COSTS
$440,900MSRP today

Still in production. A used 2023 would run roughly $260,100.

THE SPECS
Length39.9 ft
Height (incl. A/C)12.5 ft
Width8.4 ft
Interior height7.0 ft
GVWR35,320 lb
Dry weightnot published
Sleeps6
Slide-outs3
Fresh water91 gal
Grey water51 gal
Black water51 gal
Air conditioning43,500 BTU
Solar (standard)100 W
Awning20 ft
Fuel100 gal
Engine / chassisCummins ISB-XT 6.7L 360HP/800 lb-ft, Freightliner XC-R, Allison MH-3000
GeneratorOnan RV QD 8000 diesel

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

WHERE PEOPLE SLEEP
  • 1× King bed with Tilt-A-View inclining mechanism(Permanent)72×80
  • 1× Power drop-down hide-away overhead cockpit bunk(Stow-away)48×74
  • 1× Driver-side leatherette sofa bed (passenger-side optional)(Convertible)—
  • 1× Leatherette Dream Dinette booth with four belts(Convertible)—
HOW IT'S BUILT: 4/5
WallsLaminated fiberglass
FrameSteel
RoofWalk-on
UnderbellyEnclosed

Thor Motor Coach (Mixed tier): Thor Aria

YEAR BY YEAR: WHAT CHANGED
  • 2017Introduced
  • 2021Wheelbase 272", length 40'-1"
  • 2024Wheelbase 270", length 39'-11"; 40,000 BTU furnace
  • 2025100W solar and 3rd 13,500 BTU A/C become standard
  • 2027MSRP $440,860
FINDING ONE

Common: usually several for sale within a day’s drive. Why: Thor Motor Coach is a volume manufacturer; 10-year production run; still in production. Estimated from build volume and production span, not a count of live listings.

OUR TAKE

The long-running flagship couples plan - dual-vanity ensuite bath, theater seating, ten belted seats.

OTHER ARIA FLOORPLANS
3401 · 32,400 lb · sleeps 43601 · 35,320 lb · sleeps 63701 · 35,320 lb · sleeps 63702 · 35,320 lb · sleeps 43902 · 35,320 lb · sleeps 64000 · 35,320 lb · sleeps 8the whole line →
Find one for sale

Live listings for the 3901 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 Aria line ↗

Is the 3901 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.