Double D Trailers vs Sundowner: Build Quality, Safety, and Real Cost of Ownership

Sundowner is one of the most recognized names in horse trailers. You’ll see their units on dealer lots across the country. Double D Trailers takes a different path: factory-direct builds, patented safety systems, and transparent delivery nationwide.

When you’re deciding between these two brands, you’re really asking bigger questions: Which frame holds up to years of use without rust or stress cracks? Which roof keeps horses cooler in July heat? Which floor will still be solid when you resell? And what will this trailer actually cost you over 7–10 years?

This comparison answers those questions. We’ll look at the construction, airflow, insulation, loading design, warranty, and long-term costs side by side. You’ll also find a calculator to run your own numbers and see the real cost of ownership.

Safety & Build Quality

Why it matters: Rust and stress cracks don’t show up until years after you’ve written the check.

• Double D Trailers: Z-Frame alloy resists corrosion and balances strength with weight. Tubular wall posts create a stronger, insulated wall cavity.
• Sundowner: Uses a mix of aluminum and steel — aluminum is lighter, steel is stronger but rust-prone. If seams and fasteners aren’t perfectly sealed, steel components can corrode quickly. Sundowner also uses riveted panels, which can loosen, leak, and rattle over time compared to fully welded construction.

Did You Know?
Once steel starts rusting inside wall cavities, it spreads fast, often faster than owners expect. Rivets can make it harder to fully seal joints, accelerating that process.

Roof & Heat Control

Why it matters: A roof isn’t just a cover, it’s your horse’s shield against heat, leaks, and head injuries. Poorly sealed seams and metal panels can trap heat and rattle loose over time.

• Double D Trailers: SafeBump® roof = one molded composite panel. No seams, no rivets, and built-in insulation. Cushions a horse’s head if they rear.
• Sundowner: One-piece aluminum sheet, but attached with perimeter seams that can flex and leak. Horse area insulation is optional, not standard.
  

Did You Know?Inside a metal-roof trailer on a 90°F day, temps can spike above 120°F. Composite reflects heat far better.

Flooring

Why it matters: Floors carry every pound of your horses. Hidden corrosion or rot under mats can turn into catastrophic failures that aren’t visible until it’s too late.

• Double D Trailers: Choice of pressure-treated wood or rot-proof Rumber®. Rumber® needs no mats, won’t rot, and offers superior traction.
• Sundowner: Aluminum or treated wood depending on model. Both require mats. Aluminum can corrode if urine seeps beneath mats.
  

Did You Know?
Most flooring failures are hidden until it’s too late. That’s why rot-proof materials matter more than price tags.

Ventilation & Comfort

Why it matters: Horses are far more sensitive to heat and air quality than people. Without proper airflow and insulation, dehydration, stress, and respiratory issues can appear quickly on the road.

• Double D Trailers: Standard drop-down windows with bars, roof vents at every stall, and insulation throughout the horse area.
• Sundowner: Typically sliding windows, vents vary by model, and horse area insulation is not standard.
  

Did You Know?
Ventilation and insulation only work together. Without insulation, vents alone can’t prevent dangerous heat spikes.

Loading & Tack Design

Why it matters: A horse’s willingness to load (or not) is often dictated by design. Narrow, blocked entries = stress and risk.

• Double D Trailers: Patented SafeTack® swings fully out of the way. No obstructions, walk-on/walk-off designs available, and reverse slant options for horses that haul better backward.
• Sundowner: Many models include rear tack compartments (sometimes collapsible to create more space) and a front dressing/tack room. Their Super Tack models expand the front tack with swing-out saddle racks, blanket bars, and extra storage. While functional for gear, Sundowner’s rear tack designs still leave some obstruction in the loading doorway compared to a fully swing-out SafeTack®.
  

Did You Know?
Hard-to-load horses often load calmly in a SafeTack® Reverse because they can see daylight and walk straight through without backing up.

Total Cost of Ownership

• Double D Trailers: Lifetime factory-direct support, rot-proof floor options, no roof resealing = lower long-term costs.
• Sundowner: Lower initial price, but upkeep adds up, roof resealing, flooring replacement, and corrosion prevention.
  

📊 Run the Numbers: Try our TCO Calculator below to see the true cost difference.

Warranty & Support

• Double D Trailers: 8-year structural warranty, 2-year bumper-to-bumper, direct-to-factory support with mobile repair options.
• Sundowner: 8-year structural warranty, 2-year non-structural, service routed through dealers.

Did You Know?
When support goes through a dealer network, warranty claims often take longer to resolve and coverage can vary lot to lot.

Verdict: Which Fits You?

• Choose Double D Trailers if you want: Long-term safety innovations, lifetime support, and predictable ownership costs.
• Choose Sundowner if you want: A familiar brand name, dealer availability, and potentially lower upfront cost.

FAQs

Does Sundowner use steel or aluminum?
Both. Some models are aluminum, some mix aluminum with steel. That steel can corrode if not perfectly sealed.

What’s safer — SafeTack® or collapsible rear tack?
SafeTack® removes the obstruction completely. Collapsible rear tack still narrows the loading space.

Which holds resale better?
Trailers that avoid rot, corrosion, and major floor/roof repairs tend to hold value longer.

Does insulation really matter in the horse area?
Yes. Horses are highly sensitive to heat and noise. Insulation regulates temperature and deadens the “metal echo” that stresses horses.

Next Step: [Build Your Trailer Online] or [Schedule a Video Call With Our Team].

Still comparing multiple brands? See our full Horse Trailer Features Comparison Guide with 9 top manufacturers side by side.