You’ve just pulled into your driveway after a long week, and the concrete is stained with oil, grime, and moss. Your car looks dull, the patio furniture is covered in pollen, and the siding has that green tinge you’ve been ignoring. You need a gas pressure washer that can handle it all, but the choice between Simpson and Westinghouse feels overwhelming. This guide breaks down the Simpson vs Westinghouse pressure washer debate to help you pick the right machine for your home.
We’ve evaluated six popular models from both brands, focusing on power, durability, and ease of use. Whether you’re a homeowner tackling weekend chores or a DIY enthusiast with bigger projects, we’ll help you find the perfect fit. For more context on how these brands stack up against others, check our Westinghouse vs Greenworks comparison.
Buying Guide: What to Look For in a Gas Pressure Washer
Power and Performance
PSI (pounds per square inch) measures cleaning pressure, while GPM (gallons per minute) measures water flow. Together, they determine how quickly you can blast away stubborn dirt. For most home tasks like driveways and siding, you’ll want at least 3000 PSI and 2.5 GPM.
Westinghouse offers models like the WPX3600 with 3600 PSI and 2.7 GPM, while Simpson’s Clean Machine 3400 PSI delivers 2.5 GPM. Both are capable, but higher GPM means faster rinsing. If you have large surfaces, prioritize GPM over PSI.
Engine and Pump Quality
The engine drives the pump, and the pump creates the pressure. Look for reliable engines with low-oil shutdown to prevent damage. Simpson uses Honda or its own CRX engines, while Westinghouse uses their OHV horizontal shaft engines.
Pump type matters: axial cam pumps are maintenance-free and great for homeowners, while triplex plunger pumps are more commercial-grade and durable. Westinghouse’s WPX3800 features a triplex brass head pump, which is a step up in longevity.
Portability and Build
You’ll be moving the washer around your property, so wheels and frame matter. Look for pneumatic tires that handle rough terrain, and a welded steel frame that resists corrosion. Simpson’s 10″ pneumatic tires on the 3400 PSI model roll smoothly over gravel.
Westinghouse uses 10″ high-profile pneumatic tires on its bigger models, while the WPX3000 has 12″ never-flat wheels. Never-flat wheels are convenient but can be less cushioned on uneven ground. Consider where you’ll store and use the machine.
Included Accessories
Most gas washers come with a spray gun, wand, and nozzles. Check for quick-connect nozzles (0°, 15°, 25°, 40°, soap) and a soap tank or siphon hose. Simpson’s Clean Machine 3200 PSI includes a turbo nozzle, which oscillates water for faster cleaning.
Westinghouse models often include a 35-foot hose, which is longer than Simpson’s 25-foot hose. A longer hose means less moving of the machine. Also, consider compatibility with surface cleaners and foam cannons via M22 fittings.
For more on choosing the right washer for specific tasks, see our roof cleaning guide.
Final Thoughts
In the Simpson vs Westinghouse pressure washer battle, both brands offer solid machines, but the best choice depends on your needs. For heavy-duty cleaning and maximum durability, the Westinghouse WPX3800 Gas Pressure Washer stands out with its commercial-grade triplex pump and 3.6 GPM. If you want a budget-friendly option that still delivers great performance, the Simpson Clean Machine 3400 PSI Gas Pressure Washer with its surface cleaner attachment is an excellent value. Consider your typical projects and choose the one that fits your workload.
Frequently Asked Questions
Which brand is more reliable: Simpson or Westinghouse?
Both Simpson and Westinghouse are reputable brands with strong warranties. Westinghouse offers a 3-year limited coverage on parts and labor, while Simpson provides a 2-year warranty on most models. Reliability often comes down to proper maintenance, such as changing oil and using fuel stabilizer.
Can I use a Simpson pressure washer for car detailing?
Yes, Simpson pressure washers are suitable for car washing, but you should use a lower pressure nozzle (like 40°) and keep a safe distance to avoid damaging paint. Adding a foam cannon can help. For car-specific tips, check our car detailing gift guide.
What is the difference between PSI and GPM in pressure washers?
PSI measures the pressure of the water, which determines how forcefully it hits surfaces. GPM measures the flow rate, which affects how quickly you can rinse away debris. For most tasks, you need a balance of both; higher GPM speeds up cleaning, while higher PSI tackles tougher grime.
Are Westinghouse pressure washers good for large driveways?
Absolutely. Models like the Westinghouse WPX3800 with 3.6 GPM and a 35-foot hose are ideal for large driveways because they deliver high flow and reduce the need to move the unit frequently. Pair it with a surface cleaner for even faster results.
