2025 Thor Aria 3901 vs 2024 Tiffin Allegro RED 37PA

Detailed Comparison

The 2025 Thor Aria 3901 and 2024 Tiffin Allegro RED 37PA might look similar on paper, but dig into the details and you'll find meaningful differences.

Dimensionally, you're looking at 35.0 ft for the Thor Aria 3901 and 36.0 ft for the Tiffin Allegro RED 37PA. The Tiffin Allegro RED 37PA carries an extra 5,900 lbs, which affects tow vehicle requirements and fuel economy.

For sleeping arrangements, the Thor Aria 3901 offers room for 5 and the Tiffin Allegro RED 37PA can handle 7. The Tiffin Allegro RED 37PA benefits from 4 slide-out(s), expanding the interior when parked.

Looking at self-sufficiency, the Thor Aria 3901 packs 91 gal of fresh water and 600W of solar. The Tiffin Allegro RED 37PA counters with 67 gal fresh water and 300W solar.

Price is often the deciding factor. The Thor Aria 3901 starts at $313,000 MSRP, while the Tiffin Allegro RED 37PA commands $316,000 — a $3,000 gap.

Families with kids will appreciate the extra sleeping capacity and living space. Off-grid campers should pay close attention to solar wattage, battery capacity, and tank sizes. Full-timers should prioritize tank capacity, storage, and overall living comfort.

Whichever you choose, you'll be getting a capable rig. Just make sure to inspect one in person before signing.