DeWalt 3800 PSI, 3.5 GPM Gas Pressure Washer with Honda GX270 Engine and CAT Triplex Plunger Pump

Setup and first impressions

Two pulls in, the Honda fired and settled into a confident thrum. Assembly on the DeWalt 3800 was straightforward: bolt on the handle, clip the gun holder, connect the 50-foot hose, and you’re essentially ready to work. All fittings are quick-connect, which speeds things up and makes swaps between tips painless. Before first start, I checked every fastener and wheel retainer, verified oil levels in the engine and pump, and flushed the supply line—good habits with any pro-grade washer.

The frame is a welded tubular steel design with a powder-coated finish, riding on 13-inch pneumatic tires. At 112 pounds, this isn’t a featherweight, but it wheels around a driveway or jobsite without drama. The footprint is compact enough to load in a truck bed, and the low center of gravity helps when you’re rolling across uneven ground or up ramps.

Power and cleaning performance

On paper, 3.5 GPM at 3800 PSI is a lot of washer. In use, it lives up to that spec. The DeWalt 3800 has the flow to run a 20-inch surface cleaner without feeling starved and the pressure to lift stubborn algae, oxidization, and embedded dirt from concrete and textured masonry. For reference:

• 0° and 15° are my tools for heavily stained concrete, graffiti removal on hard substrates, and prep before patching. Respect the surfaces; these tips will etch if you linger.
• 25° is the day-in, day-out tip for driveways and pavers. It’s fast without being reckless.
• 40° is great for siding, outdoor furniture, and vehicles with proper technique.
• The soap tip pairs with the downstream injector for chemical application.

Real-world pressure at the wand depends on hose length, elevation, and tip choice, but the machine maintains steady power. The unloader response is crisp, so there’s no frustrating lag when you squeeze the trigger again after a release. I did not experience water hammer or hunting, which speaks well for the pump and unloader tuning.

Important note: a 3.5 GPM washer needs a proper water supply. I use a bucket test (5-gallon bucket filled in under 90 seconds) to verify flow; borderline supply will cavitate any triplex pump, and that’s a fast route to damage.

Engine and pump: the heart of the machine

The standout pairing here is the Honda GX270 and the CAT industrial triplex pump. It’s a classic formula because it works:

• The GX270 starts easily hot or cold, idles smoothly, and has Oil Alert low-oil shutdown for basic protection. Vibration is controlled; it’s not a shaker.
• The CAT pump uses ceramic pistons and includes a thermal relief valve. It runs cool for a direct-drive unit and holds pressure consistently through long work cycles.

Direct drive keeps the package compact, but it means you should avoid extended bypass times (trigger off) where heat builds quickly. I consider two minutes the upper limit; if I’m staging or moving, I shut the engine down. The thermal relief valve is a last line of defense, not a substitute for good habits.

Ergonomics and accessories

The pro-style gun and steel wand are comfortable, and the trigger pull is lighter than many consumer guns. The included 50-foot, 3/8-inch hose is a usable length with a surface cleaner and keeps the unit far enough from overspray. Quick-connect tips are cleanly machined and snap in securely.

A few helpful upgrades if you’re working regularly:

• Add a swivel to the gun to reduce hose twisting.
• Step up to 100 feet of non-marking hose (same 3/8 inch) for driveway work without moving the machine.
• A 20-inch surface cleaner is the right match for this flow rate; it speeds up flatwork dramatically.
• Consider a turbo nozzle for stubborn stains on hard surfaces.

The downstream chemical injector is the right choice for bleach and other harsh cleaners because it keeps chemicals out of the pump. Dilution varies by injector and pressure; if you need strong mix ratios for soft washing, a dedicated chemical applicator or adjustable injector is worth adding.

Mobility and build quality

The frame is stout, welds are clean, and the 1-1/4-inch tubing doesn’t flex under normal handling. The axle is a solid 5/8-inch rod with pneumatic tires that roll well over gravel and curbs. I like to check axle cotter pins and wheel hardware during setup and again after the first few hours; it’s a quick way to avoid surprise downtime. The handle locks are secure, and the unit remains stable when you tug on the hose—some washers like to tip; this one doesn’t.

If you’re servicing multiple sites, tie-down points are accessible, and the overall size makes ramp loading workable without a helper. The only portability caution is the weight: 112 pounds is fine for rolling, but lifting in and out of a van alone gets old. A small ramp or tailgate assist is a smart addition to your kit.

Noise, vibration, and user experience

This is a gas washer with a commercial engine, so hearing protection is mandatory. The tone is lower and less fatiguing than smaller, high-RPM units, and the vibration isolation is respectable. The machine doesn’t walk or skitter while running, and hose whips are manageable with the right routing and swivel.

Maintenance and reliability

Triplex pumps reward basic care:

• Keep water flow consistent; never run it dry.
• Change the pump oil on schedule and keep an eye on clarity.
• Don’t let the washer idle in bypass for more than a minute or two.
• Flush chemicals out when you’re done with detergent work.
• Winterize with a pump saver if you operate in freezing climates.

The Honda’s maintenance is minimal: periodic oil changes, air filter checks, and fresh fuel. The low-oil shutdown is a welcome safety net. Warranties here are solid—engine, pump, and frame coverage reflect the pro intent. The accessory warranty is shorter, which is standard.

What I’d change

• A hose reel mount would tidy transport and setup, though reels add weight and complexity.
• An onboard tip holder with lanyards would prevent the inevitable nozzle drop in tall grass.
• The stock hose is fine, but starting with a true non-marking, Kink-resistant hose would be a better out-of-box experience for pros.

None of these are deal-breakers; they’re quality-of-life tweaks that many users will add anyway.

Who it’s for

The DeWalt 3800 is squarely aimed at pros and serious homeowners who want commercial components without the size and cost of a belt-drive skid. It’s ideal for:

• Driveways, sidewalks, and patios with a 20-inch surface cleaner
• Prep for paint and stain on masonry and wood (with the right tip and distance)
• Fleet and equipment washing
• Boat and trailer cleaning

If you routinely leave a machine idling for long periods or run multiple wands all day, a belt-drive unit with a larger tank and remote unloader is a better fit. For everyone else, this is a compact, powerful package that punches above its size.

The bottom line

I recommend the DeWalt 3800. The Honda/CAT pairing is the right foundation, the pressure and flow are genuinely productive, and the frame/tire package makes it practical on real jobsites. It’s not a boutique belt-drive system, so you need to be disciplined about bypass times and basic maintenance, but that’s true of any direct-drive pro washer. With a few smart accessories—a swivel, longer hose, and a surface cleaner—you’ve got a reliable, fast, and versatile setup that pays for itself in speed and reduced rework.