Handles anything I throw at it2023-06-14
Used this to strip old paint off my deck and it tore through it like nothing. The triplex pump feels way more durable than my old axial pump washer.
Simpson WaterShotgun WS4000 Gas Pressure Washer
The Simpson WaterShotgun WS4000 is a robust, commercial-grade gas pressure washer built for users who need serious cleaning power for driveways, decks, siding, and job-site equipment.
Full specification
Max Pressure4000 PSI
Water Flow3.5 GPM
Engine TypeSimpson OHV Gas Engine
Hose Length50 feet
Pump TypeTriplex Plunger Pump
Cleaning units (PSI x GPM)14,000
CategoryGas Pressure Washer
Bench rank#34 of 100
Simpson
Simpson WaterShotgun WS4000 Gas Pressure Washer
- 4000 PSI cleaning power
- Commercial-grade triplex pump
- Durable steel frame
We earn a small commission on qualifying purchases through affiliate links — at no extra cost to you, and with no influence on the ranking.
Where it lands
Rank in Gas#16 of 45
Overall bench rank#34 of 100
Category average4.4 / 5
Cleaning units14,000 of 14,000 best
Verdict
The Simpson WaterShotgun WS4000 is a robust, commercial-grade gas pressure washer built for users who need serious cleaning power for driveways, decks, siding, and job-site equipment. Its triplex pump and strong engine give it excellent longevity and performance compared to consumer-grade axial pump washers, though the weight and gas engine upkeep may be a downside for casual homeowners looking for something lightweight and low-maintenance.
Key features
What you actually get
01
4000 PSI at 3.5 GPM for heavy-duty cleaning
02
Powered by a Simpson-engineered OHV gas engine
03
Triplex plunger pump with industrial-grade components
04
5 quick-connect nozzle tips for varied spray patterns
05
Pneumatic 13-inch never-flat tires for mobility
06
50-foot high-pressure hose with kink resistance
07
Steel frame construction for job-site durability
Strengths and trade-offs
Where it wins, where it costs you
+Pros
- Extremely powerful for stripping paint, oil stains, and grime
- Commercial-grade triplex pump built to last longer than axial pumps
- Comfortable spray gun with insulated grip
- Large fuel tank allows extended cleaning sessions
- Sturdy frame and tires handle rough terrain
–Cons
- Heavy unit makes it harder to maneuver alone
- Louder than electric competitors due to gas engine
- Requires regular engine maintenance (oil changes, spark plug)
- Higher price point than consumer-grade washers
- Initial pull-start can be difficult when engine is cold
Full review
Our test notes in full
The SIMPSON WaterShotgun WS4000 is a professional-grade gas pressure washer built for contractors, rental yards, and serious homeowners who need commercial-level cleaning power. At the heart of this machine is a dependable Honda GX270 engine, renowned for its durability and easy starting, paired with a CAT triplex plunger pump engineered for long service life under continuous heavy use. Together they deliver up to 4000 PSI and 4.0 GPM of cleaning power, giving you the muscle to strip paint, remove years of grime from concrete, clean heavy equipment, and tackle the toughest jobsite messes with speed and efficiency.
Built on a rugged steel frame, the WaterShotgun WS4000 is designed to withstand the rigors of daily commercial use, from construction sites to fleet washing operations. The unit rides on never-flat wheels that make it easy to maneuver across gravel, dirt, and uneven terrain without the risk of punctures slowing you down. A 50-foot high-pressure hose gives operators extended reach to work around large vehicles, buildings, and equipment without constantly repositioning the machine, while the ergonomic spray gun and lance are designed for reduced fatigue during extended cleaning sessions.
Versatility is a key strength of the SIMPSON WaterShotgun WS4000, as it comes equipped with quick-connect nozzles that allow users to switch spray patterns instantly for different tasks, whether that means a pinpoint jet for stubborn stains or a wider fan for general surface cleaning. The pump system is fully protected with thermal relief to prevent overheating during idle periods, and the overall design reflects SIMPSON's commitment to reliability in demanding environments. Backed by the brand's reputation for professional-grade construction, the WS4000 is a long-term investment for anyone who needs a powerful, high-performing gas pressure washer that can handle heavy-duty cleaning tasks day after day.
Owner voices
What buyers report after months of use
Powerful but heavy2023-08-02
This thing cleans incredibly well, but it's definitely not something you want to carry up stairs. The tires help a lot on flat surfaces though.
Great for job sites2023-09-20
I run a small landscaping business and this washer keeps up with daily use. The engine starts reliably and the pressure is consistent.
Solid investment2024-01-11
Bought this for cleaning concrete and vehicles. It's loud and needs regular maintenance, but the cleaning power justifies the price.
Related tests
