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Simpson PS4240-S Review

Simpson PS4240-S

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simpson ps4240-s

Whether you are looking for a pressure washer to tackle big, heavy duty jobs on commercial work sites, or just need a solid one to use around the home, a model like the Simpson PS4240-S is exactly the kind of machine you need. A commercial pressure washer like this one will be able to consistently deliver all of the power you need to take care of just about any job you might come across, at home or on the job. With a commercial pressure washer like the Simpson PS4240-S, you will be able to strip loose paint off of most surfaces, clean up dust from dry walling and demolition jobs, and take care of the toughest stains out there. The Simpson PS4240-S can deliver the kind of high cleaning power rating you need to deal with the most extreme cleanup jobs you can find anywhere. With this pressure washer, you’re all set.

Review Summary

review summaryThe Simpson PS4240-S is the kind of serious commercial pressure washer that is designed to offer superior power and performance over the long term. With an engine that is made by one of the top manufacturers in the world, it can consistently provide the kind of reliable power that you need to take care of big jobs quickly and efficiently. You can run the Simpson PS4240-S for an entire workday without having to give it a break, and you will rarely have to refill the huge gas tank the pressure washer has. That means you can count on the Simpson PS4240-S for the biggest jobs with no problems.

Because it is a commercial pressure washer, the Simpson PS4240-S is built with the kind of durable parts that are going to have no trouble standing up to the demanding environment of a construction or demolition site. And if you are using it around the house, that durable build will ensure that it will never break down or present any performance issues at all. Plus, because it has five nozzle options, the Simpson PS4240-S can be used just as well for small, delicate jobs like washing your car or window just as well as it can take care of big, tough jobs.


review specificationsThe Simpson PS4240-S is a gas powered commercial pressure washer that weighs 142 pounds and has a footprint of 25 x 30 x 27 inches. It has a Honda made GX390 series overhead valve engine that provides plenty of power to the axial cam pump. It has a max PSI of 4200.

Dimensions25 x 30 x 27
Engine ManufacturerHonda
EngineGX390 OHV
Power Rating16800
PumpAxial cam
Spray GunProfessional grade
Nozzle5 (0°, 15°, 25°, 40°, soap)
Hose1/4-inch x 25-foot
Hose MaterialSteel reinforced, non-marring rubber
Wheels10-inch pneumatic
Weight142 pounds
Warranty1 year

The Simpson PS4240-S has a flow rate of four gallons per minute, which combines with the PSI to give it a total cleaning power rating of 16800 units. It comes equipped with five pressure nozzles for its professional grade spray gun. It has a cold water spray and a 25 foot steel reinforced hose.


review descriptionThe Simpson PS4240-S arrives mostly assembled, and the only things you have to do to finish putting it together are attaching the hose and spray nozzle, fixing the handle in place and filling the gas tank. It only takes a few minutes and you are ready to start attacking the biggest cleaning jobs you can find. Whether you intend to use the Simpson PS4240-S for jobs around the home or take it with you to the work site, it is going to be able to handle whatever you have in store for it. As soon as you hear the Honda engine roar to life the first time, it is going to be very obvious that this is a pressure washer that means business.

The engine on the Simpson PS4240-S supports an axial cam pump that can provide a max pressure that is over four thousand pounds per square inch. You can strip paint off of surfaces with that kind of pressure. And because it has a flow rate of four gallons per minute, the Simpson PS4240-S is able to provide that high pressure spray over a broad surface, which means you will have no trouble taking care of the biggest cleanup jobs in mere minutes.

The Simpson PS4240-S is a compact machine, but it is also one that is very durably built. It is designed to hold up to the demands of a construction site, and because of that it has tough components where it counts. Its frame is made of solid welded steel. It has a hose that is made of non-marring rubber and reinforced with steel. And its wheels have ten inch pneumatic tires that will never go flat. This is the kind of machine you want when tough conditions call for a tough pressure washer. The Simpson PS4240-S has everything you need for the biggest jobs out there.


review prosLike any great machine, the Simpson PS4240-S is more than the sum of its parts. All of the outstanding features the Simpson PS4240-S has are individually impressive, but they combine to produce a commercial pressure washer that is miles above the competition in all of the areas where it counts. Below are the top five Pros on the Simpson PS4240-S. Let’s take a look at why this is such a great machine.

  1. High PSI and flow rate : On any pressure washer – commercial or otherwise – the pressure and flow rate are always going to be two of the most important features to consider. These are the only ones that are going to determine whether or not the pressure washer can deal with the really tough stains quickly and efficiently. The Simpson PS4240-S has a PSI of 4200 and a flow rate of 4 gallons per minute, which means it will have no trouble with tough jobs.
  2. Durable parts : When you are using your pressure washer on a commercial job site, anything can happen. That is why protective gear is required, and it’s why the Simpson PS4240-S is built solid to stand up to impacts and accidents. All of its parts are made of solid, high quality materials that can resist the worst impacts. This is an area where a lot of pressure washers tend to cut corners – but on the Simpson PS4240-S you’re getting the best.
  3. High quality engine : The Simpson PS4240-S has a high quality engine that is ready to handle long hours of continual work with no problems. It is made by Honda, which is one of the best small engine manufacturers on the planet, and it is designed to run the Simpson PS4240-S for a full workday or longer without any problems. It will rarely need maintenance, even after hundreds of hours of use, and it will never break down, even under tough conditions.
  4. Five nozzle options : Whether you are using the Simpson PS4240-S around your home or on the job site, you need lots of options to ensure that you can use it on a wide variety of jobs. You do not want to be stuck with a pressure washer that is too powerful for delicate jobs or that can’t deal with different conditions. The Simpson PS4240-S provides you with five nozzles of different pressures, as well as a soap dispenser, so you are prepared for anything.
  5. Small footprint : A lot of the time it is quite common for commercial pressure washers to be big, bulky affairs that you will have a hard time finding storage space for in your garage or fitting on the back of your work truck with all of your other tools. But the Simpson PS4240-S has a small footprint: it is barely two feet square and not too tall, so you will have no trouble finding enough room for it.

As I am sure you will agree, in all the areas where it really counts the Simpson PS4240-S delivers solid power and performance. Whether you are looking for a new pressure washer to use around the home or to take to commercial job sites, this one has everything you need. It is a solidly built and well designed pressure washer that has every feature you need to get big cleanup jobs taken care of fast.


review consOf course, no product is entirely perfect, and that is true for the Simpson PS4240-S as much as any other machine. The areas in which it could stand to see a little improvement are not the kind of serious problem areas that take away from all of its great features in any real way, but I still think it is important to cover them, just for the sake of being entirely thorough. Let’s take a look.

  1. Not CARB compliant : It is very difficult to find a heavy duty commercial pressure washer that has the kind of high performance engine you need for big jobs, but that is also producing fewer emissions so that it is compliant with California Air Resources Board standards. What this means is that the Simpson PS4240-S can’t be bought in California or any of the other 15 States that enforce those standards, which is really the consumer’s loss, in my opinion.
  2. Can’t use in enclosed spaces : Because it is a gas powered pressure washer, you cannot use the Simpson PS4240-S indoors – and in any enclosed space where you might be using it, like a garage or partially completed development, you have to be sure it is well ventilated with industrial fans. This is not really a Con per se, but more of a safety caution. Still, it’s important to mention it so you know that you should not use the Simpson PS4240-S in some situations.
  3. Cold water only : On a high powered, heavy duty commercial pressure washer like the Simpson PS4240-S, you would hope to get a hot water option for the water spray. This is a great feature that can really help to increase the range of jobs that the pressure washer will be able to take care of. Unfortunately, hot water sprays are not as common as one might think, and the Simpson PS4240-S does not offer one.
  4. Fairly heavy : Although the Simpson PS4240-S is not a very big pressure washer, which makes it great for storage and transport to job sites, it is a fairly heavy one. It weighs nearly 150 pounds, and while it has big enough wheels that moving it around the job site will not be very difficult, lifting it into and out of the work truck may prove a bit challenging. Be sure to lift with your legs and not your back!
  5. One year warranty : When you are spending good money on a commercial pressure washer – especially one that you will be using a lot and putting rigorous demands on – you want to be sure that it has a warranty that will cover it for a long time. On the Simpson PS4240-S you only get a one year warranty. Of course, it is so solidly built that this should not even be an issue. But a longer warranty would be better.

I think that it is pretty clear that none of the Cons the Simpson PS4240-S has can really take away from all of its great Pros. These are not the kind of issues that make me worried about its ability to provide reliable performance over the long term, and overall I think it remains a very solid, high performance pressure washer. It has everything it needs to deal with lots of different and demanding jobs.

Product Comparison

review comparisonOf course, the best way to figure out whether a particular pressure washer is the right model for you is to shop around a bit, and see what other models have to offer. That way you can get a really clear idea of just how well that pressure washer stacks up to similar ones. You also get a better sense of what a typical pressure washer should offer, and what average PSI and flow rates are over the entire market.

 Simpson PS4240-SSimpson
Generac 5997Generac
PowerStroke PS80946PowerStroke
Dimensions25 x 30 x 2728 x 28 x 3323 x 20.5 x 37
Engine ManufacturerHondaGeneracSubaru
EngineGX390 OHV420cc OHVEA190 189cc OHC
Power Rating16800160006210
PumpAxial camEasy-access axial camAxial cam
Spray GunProfessional gradeProfessional gradePro-style
Nozzle5 (0°, 15°, 25°, 40°, soap)5 (0°, 15°, 25°, 40°, soap)4 (0°, 25°, 40°, soap)
Hose1/4-inch x 25-foot3/8-inch x 35-foot1/4-inch x 25-foot
Hose MaterialSteel reinforced,
non-marring rubber
Steel reinforced,
non-marring rubber
Steel reinforced,
non-marring rubber
Wheels10-inch pneumatic12-inch pneumatic12-inch solid
Weight142 pounds165 pounds61.1 pounds
Warranty1 year3 years1 year

As you can see, the Simpson PS4240-S not only stacks up to the competition but practically blows it away in every category that really counts. It is smaller than other commercial pressure washers but has a PSI and flow rate that give it one of the very best total cleaning power ratings on the market today. It’s far better than the best residential pressure washers, which is no surprise. And it has the most durable parts and best design of just about any model out there.


review conclusionBefore you make your final decision about whether or not the Simpson PS4240-S is the best commercial pressure washer for you – although I think you already know the answer to that – let’s take one more quick look at the Pros and Cons lists, just to be absolutely sure.

Conclusion Pros

  1. High PSI and flow rate.
  2. Durable parts.
  3. High quality engine.
  4. Five nozzle options.
  5. Small footprint.

With the kind of high PSI and flow rate that can deal with any stain out there, the Simpson PS4240-S is well equipped to take on whatever job you need it for. It is solidly built and has one of the best engines in the business. It’s got plenty of options, and is well designed so it won’t take up too much room.

Conclusion Cons

  1. Not CARB compliant.
  2. Can’t use in enclosed spaces.
  3. Cold water only.
  4. Fairly heavy.
  5. One year warranty.

Those areas in which the Simpson PS4240-S did present Cons were not really that serious. Most of these are common drawbacks to commercial pressure washers. And none of them have any bearing on the overall power or performance the Simpson PS4240-S has to offer. This is still one of the best pressure washers on the market today.

Final Word

When it comes down to it, a commercial pressure washer has to be tough, well built, and dependable. These machines are designed to deal with the kind of conditions you find on a construction or demolition site. That means they have to be durable, powerful, and able to run for hours on end without having any issues. And in every one of these categories, the Simpson PS4240-S has what it takes to get the job done. It has a solid engine made by one of the best manufacturers in the world. It is able to provide the kind of superior PSI and flow rate that will allow it to handle big, tough jobs quickly and efficiently. And it is built of extremely durable parts that can take a lot of abuse without breaking down or needing repairs. When you look at the whole picture, it’s clear that the Simpson PS4240-S is one of the best.

Best Price

review pricesWith everything it has to offer, you would expect the Simpson PS4240-S to have one of the higher prices for a commercial pressure washer today. Surprisingly, it doesn’t. The Simpson PS4240-S actually has a price that falls into the middle of the range for pressure washers in its class, even though it is above average in just about every design and construction category. That means you are getting a high quality, professional grade pressure washer at an extremely reasonable price, which is good news whether you own your own business or just want to use it around the house. This is a solid pressure washer at a great price.

Simpson PS4240-S

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