Simpson CM61083 vs Westinghouse WPX3400: both are 3400 PSI gas pressure washers priced within $10 of each other. The Westinghouse adds 0.1 GPM, a fifth nozzle, an onboard soap tank and a 3 year warranty. Here is which to buy.
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Simpson CM61083 vs Westinghouse WPX3400 is a close fight between two of the most popular 3400 PSI gas pressure washers on Amazon. Both are built for homeowners who want to clean decks, driveways, siding and fences without stepping up to a commercial unit. The Westinghouse WPX3400 lists at the current retailer price as of October 6, 2026, with 3400 PSI and 2.6 GPM. The Simpson Clean Machine CM61083 lists at the current retailer price with 3400 PSI and 2.5 GPM. Based on our research into both manufacturers' published specifications, Amazon listings and owner ratings, here is how they compare and which one to buy.
Comparison Table
Power and Cleaning Speed
Both washers produce 3400 PSI, so they hit surfaces with the same force. The difference is flow. The Westinghouse delivers 2.6 GPM and the Simpson delivers 2.5 GPM. Multiply pressure by flow and you get cleaning units: about 8,840 for the Westinghouse and 8,500 for the Simpson. That is roughly a 4 percent edge for the Westinghouse, which will not be dramatic on a driveway but adds up over a large project. The engines are close in size too, 212cc for the Westinghouse and 208cc for the Simpson, so expect similar performance from either.
Engine and Pump
The Westinghouse uses a 212cc four stroke OHV engine with recoil start and an axial cam pump. Westinghouse describes the pump as maintenance free. The Simpson uses a 208cc CRX engine with low oil shutdown, which protects the engine if oil runs low, and an axial cam pump with a thermal relief valve that helps prevent overheating when you release the trigger for a while. Those are meaningful protections, and the thermal relief valve is the Simpson's best selling point. Both machines need regular oil checks, fresh fuel and winterizing at the end of the season.
Hose, Nozzles and Accessories
Both washers ship with a 25 foot high pressure hose and quick connect nozzles. Simpson's MorFlex hose is non marring, which helps if you wash finished surfaces, and the Simpson includes four tips: 0, 15, 40 degree and soap. Westinghouse adds a fifth 25 degree nozzle and an onboard soap tank, which makes it easier to apply detergent without swapping hardware. For deck and siding work the 25 degree tip is the one you will use most. Our best pressure washers for decks guide covers nozzle choice in more detail.
Wheels, Frame and Portability
Simpson lists 10 inch pneumatic tires on a welded steel frame, a 64 pound weight and dimensions of 37 by 30 by 21 inches. Pneumatic tires roll well over gravel and curbs but can go flat. Westinghouse uses 12 inch never flat wheels on a steel frame, which cannot puncture, though they can ride a little harder. Westinghouse does not list a weight on its Amazon page. Both are compact enough to store in a garage and roll to the driveway, so either one is easy for a homeowner to manage.
Price and Value
The prices are almost identical, $349.00 for the Westinghouse and $359.00 for the Simpson. Because the cheaper machine also lists higher flow, a fifth nozzle, an onboard soap tank and bigger wheels, the value edge goes to the Westinghouse. The Simpson answers with a thermal relief valve, low oil shutdown and a non marring hose. If those protections matter to you, the extra $10 is trivial. For a broader view of the category, see our best gas pressure washers guide and our driveway pressure washer picks.
What 3400 PSI Is Good For
A 3400 PSI gas washer is more than most homeowners need for light chores, but it earns its keep on concrete driveways, brick, stained decks, fences, siding and oil stained garage floors. For wood and vinyl siding, switch to a wider tip such as 25 or 40 degrees and keep the wand moving. For concrete, the 15 degree tip cleans fast, but stay a few inches back and avoid pausing on one spot, because the zero degree tip can cut into surfaces and should be used with great care or not at all. Cars, outdoor furniture and grills respond well to the 40 degree and soap nozzles. If most of your cleaning is light, an electric model may be all you need, and our best pressure washers guide covers both gas and electric options.
Setup, Maintenance and Safety
Both washers arrive with some assembly and need the owner to add engine oil and fuel before first use. Check the oil level every time you run the engine, use fresh gasoline and shut the machine off before you refuel. Connect a garden hose that can supply the rated flow, run water through the pump before you start the engine, and never run the pump dry. At the end of the season, drain the fuel or add stabilizer, and protect the pump from freezing. Always wear eye protection, closed shoes and hearing protection, never point the spray at people, pets or electrical outlets, and use the machine outdoors with good ventilation because the engine produces carbon monoxide.
Reading the Owner Ratings
Amazon owner ratings favor the Westinghouse, at 4.5 stars across 4,502 ratings versus 4.3 stars across 2,038 ratings for the Simpson. Star averages on gas equipment mix several things together, including shipping damage, engine starting problems and ordinary wear, so treat them as a rough signal rather than a verdict. Read the recent low-star reviews on whichever listing you pick, look for repeated complaints about the same part, and check that the seller is Amazon or an authorized dealer so any warranty claim goes smoothly.
Warranty and Support
Westinghouse backs the WPX3400 with a 3 year limited manufacturer service warranty according to its Amazon listing. Simpson's warranty terms were not on the listing, so confirm the current terms on Simpson's site. Check the terms for any machine before you buy, because warranty coverage on pressure washers often depends on registration and use.
Who Should Buy the Westinghouse WPX3400
Most homeowners. If you want 3400 PSI for decks, driveways, siding, fences and cars, with an onboard soap tank, five nozzles and a 3 year warranty at the lowest price, this is the one. It also has the larger owner base on Amazon, which is useful for reading about long term reliability.
Who Should Buy the Simpson CM61083
Buyers who want the Simpson pump with a thermal relief valve, a non marring hose and low oil engine shutdown. If you are comparing both and the $10 price difference does not matter, the Simpson's protective features are a legitimate reason to choose it.
Final Verdict
The Westinghouse WPX3400 is our pick. It costs less, delivers more water and includes more accessories with a clear 3 year warranty. The Simpson Clean Machine CM61083 is a good alternative for buyers who value its pump protections and hose. Either will clean a deck or driveway well. Always wear eye protection, keep the spray away from people and pets, and read the manual before you start.
FAQ
Is the Westinghouse WPX3400 better than the Simpson CM61083?
For most buyers, yes. It costs $10 less, has 2.6 GPM versus 2.5, adds a fifth nozzle and an onboard soap tank, and lists a 3 year limited warranty. The Simpson has a thermal relief valve, low oil shutdown and a non marring hose.
Is 3400 PSI too much for a deck?
It can be. Use a 25 or 40 degree nozzle and keep the wand moving and at a distance, because high pressure can gouge soft wood. Test in a hidden spot first and avoid the zero degree tip on wood.
What does GPM mean on a pressure washer?
GPM is gallons per minute, the amount of water the machine delivers. PSI is the force. Multiplying the two gives cleaning units, a rough measure of how fast the washer cleans.
Do I need to winterize a gas pressure washer?
Yes, if you live where it freezes. Drain the pump and add a pump saver, and stabilize or drain the fuel. Check the manual for your model's steps.
Can I use detergent with these washers?
Yes. Use the soap nozzle for low pressure application. The Westinghouse also has an onboard soap tank. Use detergents rated for pressure washers and rinse with a higher pressure nozzle.
