Simpson PS4240 Pressure Washer: A Benchmark in High-Pressure Cleaning

Simpson PS4240: Great Commercial Machine That Doesn't Cost Too Much

Aug 29, 2023

Most residential pressure washers offer a maximum pressure between 1200 and 2400 PSI. While this capability is enough for regular light cleaning work around your home, those machines don't have what it takes to perform heavy-duty tasks, especially when you need constant powerful water jets for an extended period.

In these situations, it's not unusual to opt for a commercial model like the Simpson Powershot 4200. It's true that this model may cost you a lot more, but its powerful engine and quality construction promises a wider range of applications, such as lifting the toughest oil stains from your garage floor. Let's find out what this pressure washer can do and whether or not it will be overkill for you. Check out the Simpson PS4240 review below.


The Simpson pressure washer, 4200 PSI is a commercial gas pressure washer that is made for a professional washing business as well as heavy-duty residential uses


Easy to assemble
Value for money

If you need top-class reliability and extreme power, this 4200 PSI machine is one of the best choices coming from a reputable brand. It can help you remove the toughest grime and mold from any surface without spending too much on models like the Simpson PS60843 or the Simpson PS60869.


  • • Powerful Honda GX390 engine
  • • Durable and reliable
  • • Multiple nozzle tips included
  • • Easy to start


  • • Need to be careful of the powerful water jet
  • • Not CARB compliant
  • • Heavy to move around
  • • Only 1-year warranty

Simpson PS4240 Review

Overall Design

Simpson has used welded plates and tubular steel to make the frame of the PS4240. This steel axle connects two rubber tires together and gives support for the entire machine. On the outside, the powder-coated black finish prevents chemicals and water from corroding and rusting the steel. This tubular frame also acts as a protective roll cage for the gas tank, the pump, and the front of the Honda engine.

   ➜ RELATED: Ryobi Ry142300: Best Electric Pressure Washer?

In addition to this sturdy frame, the handle has two thumbscrews bolted into it, providing a reliable way for you to lift or pull the Simpson PS4240H. These screws are also easy to remove so you can loosen them to make this pressure washer more compact for storage.

On top of that, the rest of the machine consists of other quality components, including brass fittings, pneumatic tires, steel wheels, and a AAA pump. But, here is the thing. By using these reliable and durable parts, Simpson must sacrifice some other areas in the design of the PS4240. For example, at 141 pounds, this pressure washer is not a lightweight machine.

Fortunately, the designers have done an amazing job of distributing this weight properly across the machine so it won't tip over easily and you won't face any major trouble moving it around. Thanks to the big tubular handle and pneumatic tires, the Simpson 4200 PSI pressure washer is fairly maneuverable on multiple surfaces.

The included hose is 50 feet long and has a diameter of 3/8. On each end of this abrasion-resistant hose, there are also quick-connect couplings. Additionally, the spray gun comes with an ergonomic design with a bold lockout and a full-length trigger for better comfort and control and two mounts on both sides for the 50-inch hose.

The water hose

The water hose Via: Amazon

The Honda GX390 4200 PSI 4 GPM gas pressure washer is also equipped with multiple niceties that make it stand out and become a better overall machine. For example, you will find five quick-connect nozzle tips, including a soap tip and other angles from 0° to 40°, that fit snugly into the rubber seat. However, while there are so many things that come with the PS4240, they are nicely put together in a single package.

   ➜ RELATED: Sun Joe SPX3000: Great Electric Pressure Washer For Medium-Duty Cleaning Tasks



As a commercial-grade pressure washer, it is not surprising that Simpson equips the PS4240 with a powerful motor like the Honda GX390. With a displacement of 389CC, this 12HP motor can produce 20lb-ft torque at 2500RPM. On top of this powerful torque - which means the most to the cleaning capability of a pressure washer - it also includes an extra safety feature that automatically shuts itself down to avoid engine failures if it detects a low oil level.

The Honda GX390 engine

The Honda GX390 engine Via: Amazon


The component that drives the water is the AAA industrial 4.0 GPM 4200 PSI pump, which is connected to the Honda engine via a direct-drive mechanism. It has huge dual ball bearings to provide better friction and wear resistance while making the pump last longer.


In our test, we used an aluminum pool cage and a patio that hasn't been cleaned for years. They were full of crud, mildew, and mold build-up, making them a perfect test bed for any deep-clean machine. To see how the Simpson PS4240 would perform on its own, we didn't use any chemicals.

Even if you're already familiar with a Simpson cleaning machine, we recommend that you read the user manual before using it. The startup alone requires several steps before you can hear the roar of the engine. Like any model with a direct-drive pump, don't forget to hook it up with your water supply first before turning on the switch, then move the choke, and finally pull the engine cord.

   ➜ RELATED: Simpson Cleaning MSH3125 Megashot Gas Pressure Washer Powered By Honda

During our test, the heart of this pressure washer, the Honda GX390 engine, started without hassle, which is a pretty big deal if we consider how Honda engines usually perform on other models. They are indeed durable and reliable, but kicking off those machines is typically an issue of its own.

When we pulled the trigger, there was immediately a sudden and powerful water jet coming out of the tip of the sprayer. You should keep this in mind when using it the first time; otherwise, it may catch you off guard with its strength. We don't want to sound exaggerated, but be careful and hold a stable footing when you bend over or reach a high area, or the powerful blast may make the cleaning a little difficult.

On the other hand, this strong water flow translated well into an impressive cleaning result. We went through everything quickly with the Simpson PS4240 and had a noticeably clean, freshened surface at the end of the cleaning session.


When you spend a lot of money on a machine like the Simpson PS4240, it is expected that you would have a long warranty period. It's even more important when you are planning to put it through rigorous demands. Unfortunately, this machine comes with only a 1-year warranty. While it is supposed to last several years with ease, thanks to all the durable components, it's always better to have a longer warranty if possible.


There are plenty of quality models from other manufacturers that can bring the same pressure level of 4000PSI.

#1- Pressure Pro E4040HC

Pressure Pro E4040HC

Pressure Pro E4040HC Via: Amazon

This premium model features the same Honda GX390 engine. Like the Simpson 420cc engine review above has pointed out, it can deliver 13HP, enough to provide a strong water jet for various cleaning tasks like removing stubborn oils stains from your floors or lifting off old paint on walls. Like the Simpson PS4240, this machine is built to last with a long service life.

The Pressure Pro E4040HC also comes with plenty of unique safety mechanisms to reduce the risk of operator malfunction. For example, there are multiple built-in thermal sensors that can detect overheating during the cleaning sessions. Whenever the machine begins to run hot, these sensors will automatically shut down the system, allowing the machine to cool down. This is especially crucial over long periods when your pressure washer may end up with catastrophic engine failure.

Pressure Pro has equipped this model with reinforcement in the water hose to make sure that it doesn't split or leak due to the high pressure. Thanks to aircraft-grade material, the frame of the E4040HC is incredibly durable and robust, preventing damage from the tools or other machines pumping into it. Additionally, it has high-quality mountings to reduce vibration in use as much as possible, so your experience with this machine will be expectedly more enjoyable than with a typical model at the same price point.

With gas pressure washers, it's common to forget about the gas level. If you take no notice of it and your gas engine runs out of fuel, the internal components may be severely damaged and require repair from a professional technician. Luckily for you, the E4040HC comes with a low-oil shutdown feature that will turn off the engine before the fuel tank dries up entirely.

Overall, while the Pressure Pro E4040HC is certainly more expensive than the Simpson machine, its top-notch built quality and safety features are totally worth considering.

#2- Briggs & Stratton Elite 4000

Briggs & Stratton Elite 4000

Briggs & Stratton Elite 4000 Via: Amazon

The Elite series from Briggs & Stratton is always a decent option for any budget-conscious customer. The Briggs & Stratton Elite 4000 is a great all-around machine that can deal with heavy-duty residential work while not costing too much.

This pressure washer uses a 420cc Briggs & Stratton 2100 engine instead of the popular Honda GX390 to deliver a maximum pressure of 4000PSI. The choice to use an in-house engine doesn't only bring down the cost, but thanks to the Overhead Valve (OHV) technology, it also runs cooler and can last longer. The fuel tank and motor are mounted on the frame, which in turn is directly placed on the pneumatic tires to make it easier for users to move the pressure washer between cleaning sites.

The Elite 4000 also comes with a unique automatic detergent infuser. This mechanism allows the machine to use cleaning detergent directly from off-the-shelf products. It doesn't require mixing the cleaning solution beforehand; instead, the infuser will get this job done on its own and provide the correct ratio before spraying.

#3- Generac 6565

Generac 6565

Generac 6565 Via: Amazon

The Generac 6565 is another pressure washer that uses the 420cc OHV engine to deliver a pressure of up to 4200 PSI, making it a worthwhile consideration for deep cleaning and other tough cleaning tasks. At nearly the same price point, this Generac model is slightly more powerful at 12.3HP.

Like the Briggs & Stratton Elite 4000 mentioned above, the motor in this model uses an overhead valve design to make sure the machine runs quieter with better fuel efficiency. The low-oil sensor in the Generac 6565 will automatically shut down the engine to protect it when the tank runs low on fuel, prolonging its lifespan.

Any good pressure washer needs a reliable pump. Not only is it necessary for the machine to deliver a stable jet of water, but this also makes sure your machine can last for a long time. On the Generac 6565, you will find a pro-grade Triplex pump. Compared to the typical axial cam design, this pump can last several times longer by dissipating heat at a superior rate. Connecting the water hose to this pump is also more convenient: since it is located at a higher position, you don't need to bend down anymore.

Even though the maximum pressure is 4200 PSI, you can adjust it freely for different cleaning jobs and use one of five Quick-Click nozzle tips for more versatility: 0°, 15°, 25°, 40°, and soap. The hose is a good length at 50 feet, enabling a much larger cleaning radius without moving the unit around too much.

However, the Generac 6565 doesn't follow the California Air Resource Board (CARB) regulations. It releases many unhealthy fumes and is not available in states that do adopt this standard.

Final Verdict

For heavy-duty cleaning tasks, it's always great to have assistance from a well-built, tough, and dependable machine that can deliver a powerful water jet for hours without running into issues.

As our Simpson PS4240 review has pointed out, this machine ticks all the boxes when it comes to a commercial pressure washer like that. While the Honda GX390 engine can provide a superior flow rate at high pressure, the durable frame and components can withstand all the abuse you throw at it during a cleaning session, making it one of the best rated pressure washers on the market.

Related Product Reviews

Greenworks GPW1501: Reasonable Choice For Home Use?

While you can cover most of your household cleaning tasks with simple tools and a little hard work, there are certain things that you just can’t. Having said that, when working on your dirty driveways, walkways, wood decks, cars, concrete or brick walls, it’s extremely helpful to have your pressure washer available. The machine will offer powerful water streams that blast off all stains, mildew, grime, and other dirty stuff on the targeted surfaces.

Ryobi RY142300: Best Electric Pressure Washer?

A good pressure washer is an underappreciated cleaning tool that I think everyone should have in their toolshed

Sun Joe SPX3000: Great Electric Pressure Washer for Medium-duty Cleaning Tasks

Are you looking for a lightweight pressure washer for small to medium-duty cleaning tasks? Electricity-powered machines are usually easy to operate and carry around compared to their gas-powered counterparts. But which model is the right choice? The Sun Joe pressure washer SPX3000 would be a great choice for home use.

Simpson Cleaning MSH3125 MegaShot Gas Pressure Washer Powered by Honda

If you have a considerable amount of outdoor space, you wouldn't want to be moving around with a scrubbing brush and hosepipe. It would be exhausting and ineffective. With so many different brands, models and types of pressure washers in the market, the ideal solution for a spic and span backyard, garden paths, and vehicles is at hand!

Ryobi 1600 PSI Pressure Washer: Compact but Powerful Pressure Washer for Residential Use

House cleaning is never easy for all of us, especially for me. Keeping the inside of the house clean and tidy is “a real challenge” even though there is a lot of equipment available. How about my garage, my little garden? Oh no, I can’t imagine it! One day, I got the idea of buying a pressure cleaner. I started to research about this equipment and decided to buy the Ryobi 1600 PSI electric pressure washer.

TOP Reviews Suggested

Deep cleaning your house, both indoors and outdoors, is never an easy task. Instead of purchasing a lot of equipment, a high-quality pressure washer might offer tremendous support.The thing is, how do you go about finding the best pressure washer? We have some options for you to choose from.