Simpson MSH3125-S Pressure Washer Review

The Simpson MSH3125-S is the gold standard of residential pressure washers, offering the best parts and accessories in its class with more than enough cleaning power for any project you’ll have at home. To top it off, it also has a very reasonable price tag.

Man using the Simpson MSH3125-S gas pressure washer


Use the table below to get an overview of the Simpson MSH3125-S. Our review will take a closer look at how everything works, but this should give you an idea of what to expect in terms of cleaning power, features and more.

EngineHonda GC190
Fuel tank0.475 gal.
Pressure3,200 PSI
Volume2.50 GPM
Cleaning units8,000.00
Wheels10.0 in.
Hose25 ft.
Wand16.0 in.
Nozzles0°, 15°, 25°, 40°, soap
Dimensions34.0 x 21.0 x 24.0 in.
Weight65.0 lbs
Warranty1-5 years


The MSH3125-S can be unboxed and ready to use in about 15 minutes. Barely any assembly is required, and you don’t need any extra tools to complete the process (however, it’s helpful to have a box cutter to remove the packing materials).

In the box, you’ll find the following items:

  • (1) Simpson MSH3125-S gas pressure washer
  • (1) MorFlex high-pressure hose (25 ft.)
  • (1) Rear-entry spray gun
  • (1) Steel wand (16”)
  • (5) Quick-connect nozzles (0°, 15°, 25°, 40°, soap)
  • (1) Detergent siphon
  • (1) Simpson premium engine oil (10W-30)
  • (2) Hand knobs

The pressure washer comes out of the box in two pieces: the base (i.e. the lower part of the frame that holds the engine and pump) and the handle. To connect the two, the handle simply slides onto the base and secures into place with the two included hand knobs.

From there, the accessories can be put together and mounted in the dashboard at the top of the handle. Screw the wand onto the spray gun; then, the spray gun sits in the holster on the right, the hose hangs from the large hanger on the left and the nozzles are held in the rubber grommets along the top.

The last thing to do is add fuel and oil to the engine. The included oil packet will cover you on oil, but of course, you will need to supply your own gas (about a half gallon).


The MSH3125-S may be a residential pressure washer, but it’s made to the same standards as Simpson’s commercial units. The frame is 16-gauge steel, and it rolls on heavy-duty 10” pneumatic wheels using a solid axle, which makes it extremely easy to maneuver no matter the type of terrain.

Simpson MSH3125-S gas pressure washer

Simpson MSH3125-S

The MSH3125-S has a 90% recommendation rate (based on 5,000+ verified reviews from six sources). It’s the best-selling gas pressure washer at Amazon and Pressure Washers Direct, and it’s top three at Home Depot and Lowe’s.

3,200 PSI at 2.5 GPM is considered on the higher end of cleaning power for the residential category. It’s not much higher than other gas units (the average is 3,000 PSI), but it’s noticeably higher than an electric unit (these average around 2,000 PSI). With this much power, you can clean just about anything: houses, driveways, decks, cars, etc.

Regardless, what’s important here is how you get this performance: a Honda GC190 engine and an axial cam pump from OEM Solutions. The GC190 is Honda’s best consumer-grade engine, and it has a strong track record of reliability. While the pump doesn’t have the same public reputation, it’s an equally good choice because it’s made in-house (OEM is Simpson’s sister brand, so they ensure quality control).

The included accessories are all premium, with the biggest upgrades being a braided hose for puncture resistance and a rear-entry spray gun to keep the hose out of your way as you’re working. Brass fittings are also used across the board for durability.

Detergent is injected using a siphon, which some people consider less convenient than an onboard tank because you have to use your own bucket to hold the solution. This can be a matter of preference, but generally, siphons are actually easier to use and don’t require as much cleanup.


The MSH3125-S doesn’t have any problems that we consider dealbreakers, but there are a few small drawbacks and design flaws that are worth mentioning for the sake of transparency:

  • The starter is in a tight spot. The frame has a rise in the front to act as a protective guard for the engine, but it’s so close to the starter that it can be a little difficult to grab the handle if you have bigger hands.
  • The warranty varies by part. Residential pressure washers usually have a 2-3 year warranty that includes all major components, but this warranty varies, giving you a longer term on some parts but a shorter term on others (in this case, 1-year pump, 2-year engine, 5-year frame).

Frequently asked questions

Get answers to some of the most common questions about the Simpson MSH3125-S. For additional help, you can reach out to us at any time, but in some cases, you may need to contact Simpson directly.

Is Simpson a good pressure washer brand?

Simpson is known for professional quality. They have the largest catalog of pressure washers, and their parent company, FNA Group, is one of the most respected manufacturers in the industry.

Read more about them and see alternatives in our guide to pressure washer brands.

Where is the MSH3125-S made?

All Simpson pressure washers are made in the United States, including the MSH3125-S. The brand is based in Wisconsin, but they have manufacturing facilities in several other states as well.

How long will the fuel tank last?

The Honda GC190 engine on the MSH3125-S will run for about one hour on a full tank of gas, assuming you’re cleaning the entire time. If you’re cleaning intermittently, it could last 2-3 hours.

Read more about this engine in our guide to Honda pressure washers.

Compare similar pressure washers

Use the product carousel below to compare the Simpson MSH3125-S to competing pressure washers with similar cleaning power and features. For more alternatives or for help choosing, read our guide to the best pressure washers.

Simpson MSH3125-S gas pressure washer

Simpson MSH3125-S

  • 3,200 PSI and 2.5 GPM
  • Honda GC190 engine (6HP)
  • OEM Solutions axial cam pump
  • 25 ft. hose, 16″ wand and 5 nozzles
  • Detergent injection via siphon
  • Warranty varies by part (1-5 years)
Ryobi RY803001 gas pressure washer

Ryobi RY803001

  • 3,000 PSI and 2.3 GPM
  • Honda GCV160 engine (4HP)
  • Axial cam pump
  • 35 ft. hose, 20″ wand and 5-in-1 nozzle
  • 128 oz. onboard detergent tank
  • 3-year warranty
Generac 7122 gas pressure washer

Generac 7122

  • 3,200 PSI and 2.7 GPM
  • Generac engine (196CC)
  • Axial cam pump
  • 30 ft. hose, 20″ wand and 5 nozzles
  • 64 oz. onboard detergent tank
  • 3-year warranty