The Best Gas Pressure Washers

What’s the best Gas Pressure Washer? We review several gas-powered pressure washers we feel are worth your money, as well as discuss some important things that you should know when choosing the best gas pressure washer for your needs and budget.

When it comes to choosing a pressure washer for big projects, such as stripping paint or cleaning decks, patios, sidewalks and exterior siding, or for multiple projects requiring frequent use such as with commercial use, a gas powered pressure washer is the best option. It delivers higher pressure than an electric model that helps us do the job much quicker and better. It also offers supreme portability because you’re not restricted by the length of the cord. And in remote locations where there’s no electrical hookup or in very harsh environments like construction sites, a gas pressure washer could be the only option that works for you.

While you might have some intuitive sense for how much size and power you require from an electric pressure washer, as we mostly use it for washing cars, most homeowners are less familiar with gas-powered pressure washers. So, how much PSI & GPM do you really need? What criteria should you consider when selecting a gas pressure washer? What’s the best gas pressure washer on the market? Here is everything you need to know when deciding to purchase one for yourself:

Best Gas Pressure Washer: Editor’s Picks

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After many hours of research, we think the Generac SPEEDWASH 3200 PSI Pressure Washer is the best gas pressure washer for most people. This is a complete pressure washing system that provides ALL the tools you need for every application. It delivers the raw cleaning power you need to accomplish the toughest cleaning tasks. And because of the fact that the engine is designed and made in the USA, it’s built with the quality and reliability in mind. As long as you store this machine correctly and maintain it well, this pressure washer should last you for many years.

If you really want to remove dirt quickly or make money with your pressure washer, we suggest trying the Simpson PowerShot Professional 4200 PSI Gas Pressure Washer. This is one of the best gas pressure washers of Simpson Cleaning – one of the leading manufacturers of outdoor power equipment for residential, commercial and industrial use. All of Simpson gas pressure washers are produced in a 228,000 sq-ft (4 football fields large) manufacturing plant in Decatur, Arkansas with a very high quality and less prone to damage when used in extreme, harsh environments. That’s probably why they are so popular in the USA.

Plus, the Honda engines are very reliable engines that provide the safety,  easy-start convenience, improved power, greater fuel efficiency, longer run time and quieter operation. With 4 GPM and 4200 PSI at your fingertips, you can blast through mud, dirt and debris quickly and more easily, boosting productivity and saving money.

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Gas vs. Electric Pressure Washer

Which type of pressure washer is better? Gas-powered or electric pressure washers? These are very common questions when it comes to choosing a new pressure washer for home. Here is what we discovered:

Gas Pressure Washer

Like gas-powered water pumps, gas pressure washers have one huge advantage over electric models: they have much higher pressure and flow rates (most electric models have an upper limit of about 2000 PSI, 1.4 to 1.5 GPM, while most gas-powered models produce around 2800 PSI / 2.5 GPM and go up from there). They can handle any job a homeowner can throw at them, including heavy concrete cleaning. The best gas pressure washers, like the Generac SPEEDWASH 3200 PSI Pressure Washer, offer many features to match different applications, from light-duty projects such as washing cars, cleaning decks to heavy-duty projects such as stripping paint.

Did You Know? Gas-powered washers can clean 2-3 times faster than electric powered washers due to high flow and pressure washer ratings.

Gas pressure washers are also portable, they offer great flexibility since they aren’t tethered by an electrical cord. This is great if you need to clean a fence or shed farther from your home. Or, maybe you need to take your pressure washer to clean your cabin and power sources are limited.

On the other hand, gas-powered pressure washers are more durable so you don’t have to worry about replacing stuff like brass quick-connect couplers. Electric models use plastic ones which have to be replaced more often. Because of that, most pressure washers that we see on the jobsites are gas-powered. Some of the best gas pressure washers, such as the Simpson PowerShot Professional 4200 PSI Gas Pressure Washer, offer up to 10-year warranty while most electric models are 2 years or less.

But all that power, portability and durability comes with some requirements. You’ll need to perform some simple engine maintenance including monitoring gas and oil levels and draining or treating the fuel for storage. Gas pressure washers are also going to be louder than electric pressure washers. They tend to also be heavier, although all models are mounted on wheels.

Electric Pressure Washer

Electric power washers offer benefits in their size, being small, compact and ready to take on lighter duty cleaning tasks. They are a common choice for small decks and patios, outdoor furniture, and other small jobs that require mainly cleaning instead of stain removal.

Electric pressure washers are much smaller and half the weight of a gas machine, and also quieter. They start and stop conveniently and do not need winterizing if brought indoors, and their small size makes them easy to store.

A downside is that they often aren’t as powerful as a gas-powered pressure washer. They also have a shorter lifespan than gas pressure washers because they are designed for less frequent use. Plus, they need a power source, making jobs away from the house a bit more difficult to tackle.

Our Thoughts

Obviously we can’t tell you which one is better because it’s not that simple. Electric pressure washers have the upper hand when it comes to low price, compact dimensions, small weight, nearly zero maintenance and ease of use. They can also be used indoors. On the other hand, gas-powered pressure washers are much more powerful and feature heavy-duty parts.

Personally, we always prefer gas-powered to electric. The best gas pressure washers can do just everything that an electric model can. With accessories, we can use our gas pressure washer for light-duty, medium-duty, and heavy-duty projects. The power and portability of a gas-powered pressure washer make the jobs much quicker and easier.

Here is what one of our friends said when we ask him about gas and electric pressure washers:

I own both a gas and electric pressure washer. One of my neighbors has electric and the other has a gas hot water machine. My neighbor with the electric is always borrowing mine or the others machine. The electric is great but not best for certain jobs. My gas I can always change the nozzle and go at any job. But the electric will never work great for oil stains on a concrete pad.

How to Buy the Best Gas Pressure Washer?

Here are some tips that will help you narrow down your search for the best gas-powered pressure washer.

What Size Do You Need?

  • PSI: Pounds per square inch measures the pressure, or cleaning force, of water created through the pressure washer. Use the PSI rating to help you determine how powerful the water stream will be.
  • GPM: Gallons per minute measures the volume of water delivered through the pressure washer. This number will help you determine how fast the pressure washer will clean, and how effectively it will rinse away debris.

The power output of a gas pressure washer is determined by Cleaning Power Units (CPU) – this is one of the least understood, yet most important rating for pressure washers.


The greater the CPU the greater the ability the machine has for cleaning deeply and effectively. Often a buyer is so focused on the PSI of the machine that they do not take the time to look at the CPU.

For example, a gas pressure washer may have 2800 PSI and 2 GPM giving it a CPU of 5600. Another unit has only 2400 PSI but has 3 GPM giving it a CPU of 7200. In this example the lower PSI unit has more than 20% greater cleaning power than the higher PSI rated unit. The result is that the 2400 PSI machine will be able to clean an area 20% faster than the 2800 PSI unit. The CPU rating allows you to compare different machines effectively.

Now consider this, a garden hose will be about 6 GPM and 10 PSI giving it 60 CPU. With a standard spray nozzle attached to the garden hose you can get around 5 GPM at about 40 PSI generating 200 CPU. We all have seen the difference of how much more effective a simple spray nozzle is at cleaning dirt off of surfaces. Trying to clean your driveway with your garden hose spray nozzle generating 200 CPU is fairly ineffective.

However, if we take a midrange pressure washer a 2 GPM and 2500 PSI (5000 CPU) this is a staggering 25 times increases over a spray nozzle. A gas pressure washer at 4 GPM and 4000 PSI, like the Briggs & Stratton ELITE4000 Gas Pressure Washer, is an incredible 16000 CPU. It is not difficult to imagine the difference in efficiency.

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So, Do I really need a gas pressure washer with higher rating? It all depends on you. A machine with lower ratings can do almost all the jobs a more powerful machine can do. But a machine with higher ratings will clean much, much faster.

Components of the Gas Pressure Washer

To select the best gas pressure washer, it’s important to have an understanding of the components and what they do. Every pressure washer is made up of 2 main parts:

  • Pump
  • Gas Engine (Power Source)

How Does a Pressure Washer Work?

1. Pump

The pump is the most important part of a gas-powered pressure washer. It receives water from your garden hose, pressurizes the water to thousands of PSI then sends it out. The best gas pressure washers should be equipped with a reliable pump and have features that keep the pump from overheating. There are several common types of pumps:

The wobble pump is on the low end of quality. The basic design consists of a plate that is offset and then forced to wobble by several pistons pushing against it. There are two or more pistons pushing against a plate at different intervals which makes it the plate “wobble” very quickly, creating pressure. This style is very inefficient (70% due to piston spring resistance on each stroke).

The axial pump is very similar in design but has a larger oil reservoir and larger bearings. This allows the pump to run cooler and results in longer pump life. The larger cylinders in the axial pump allow it to generate more PSI and GPM than a standard wobble pump. Axial pump performance is an improvement over the wobbles pump but still suffers from piston spring resistance. The Generac SPEEDWASH Gas Pressure Washer and the Briggs & Stratton S3200 Gas Pressure Washer are two of the best gas pressure washers that use this type of pump.

The triplex pump is a piston and plunger design featuring three piston rods that are synchronized together creating a smoother pressurization resulting in more consistent flow that nearly eliminates pulsation. These are often on much higher quality machines. A triplex pump is much more efficient than an axial-style pump. The triplex pump also run much cooler and lasts longer. Another benefit of this design is that a Triplex pump generates much less heat and therefore runs cooler than an axial-style pump.

The Simpson PowerShot Pressure Washers are some of the very best gas pressure washers that use the triplex pump. That’s probably why they are much more expensive than other models of the same power.

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2. Gas Engine

Similar to the gas engine of an air compressor, the engine of a gas pressure washer is the power source that powers the pump. The more powerful the engine (rated in HP), the greater the PSI and GPM that can be produced.

Two most important things to ask about the engine is how much horsepower it has and how many hours it is rated for. The better quality the engine, the longer it will last. However, quality does not necessarily translate into more power. You can have some excellent quality engines that can last you a very long time, but they were built to generate fairly low power.

When it comes to gas engines, the Honda, Generac, Briggs & Stratton and Karcher engines are the most reliable brands on the market. These engines are very durable and stable. In terms of energy efficiency, Honda is best.

Best Gas-Powered Washer Pressures Reviews

1. Generac SPEEDWASH 3200 PSI /  2.7 GPM Pressure Washer – Best Residential Gas Pressure Washer

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The Generac’s SPEEDWASH 3200 PSI Gas Powered Pressure Washer is the best gas pressure washer for the first time users but even someone like myself I just adjust the nozzle to apply the correct pressure. This is a complete cleaning system which includes a family of innovative cleaning attachments to deliver better cleaning results in less time.

The unit includes an Axial Cam pump which is easy to maintain and a detergent tank so you’re not dragging a bottle around the house with you. The powerful Generac 196cc OHV engine is a reliable gas engine which delivers maximum cleaning performance. The SpeedWash comes with Powerdial ergonomic spray gun allows you to easily adjust the pressure needed between 4 different tasks – car, wood, concrete and soap. Turbo nozzle attachment with rotating pinpoint stream is designed to remove stubborn dirt and grime off tough surfaces 30% faster than standard nozzles. And there are several other great features that you can see on Generac’s website or on Amazon.

Overall, we think this is an ideal pressure washer for home use and we would recommend it to anyone looking for a home use washer.

2. Simpson PowerShot Professional 4200 PSI / 4.0 GPM Gas Pressure Washer – Best Commercial Pressure Washer

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The Simpson PowerShot Professional 4200 PSI Gas Pressure Washer is the best gas pressure washer for heavy-duty and commercial projects. With a powerful Honda engine, reliable triplex pump and welded steel frame construction, this gas pressure washer is great for construction, equipment upkeep, facility & fleet maintenance cleaning. The Honda GX390 engine with low oil protection provides the ultimate reliability, plus easy-start convenience, improved power, greater fuel efficiency, longer run time and quieter operation.

The feature that makes the Simpson PowerShot one of the absolute best gas pressure washers on the market is its AAA industrial triplex plunger pump. This pump rated up to is highly efficient and minimizes engine load. It contains dual oversized ball bearings for better wear, friction resistance and longer lasting performance in the toughest cleaning environment. It is also equipped with the Easy-Start feature and carries a 5-year limited commercial warranty.

Overall, this gas-powered pressure washer met all our expectations, if you’re looking for a heavy duty unit this would be a great choice. We would recommend to anyone looking for a good higher end pressure washer.

3. SIMPSON MegaShot 3100 PSI / 2.5 GPM Gas Pressure Washer – Best Price Gas Pressure Washer

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If you’re looking for a high-quality gas pressure washer with minimal investment, the SIMPSON MegaShot 3100 PSI / 2.5 GPM Gas Pressure Washer is a perfect choice. This is not only one of the best gas pressure washers on the market but also the most popular gas model of all time. Because it’s lightweight, easy to maneuver and can be transported by one person, this is a perfect option for homeowners.

The Simpson MegaShot has a durable Honda GC190 engine, which has earned its place at the top of the small engine heap for being quieter and easier to start than other engines in its class. The OEM Technologies axial cam pump with patent pending PowerBoost technology provides high pressure at the nozzle resulting in great impact and cleaning performance.

Unlike the PowerShot, at this price you’d get only a 1-year pump warranty and 2-year engine warranty from the MegaShot. But don’t worry because this pressure washer is very durable. Amongst all of the consumer-grade pressure washers we carry, this model has been by far the most reliable and durable pressure washer in this category.

4. Karcher G2700 2700 PSI / 2.5 GPM Gas Power Pressure Washer – Best Portable Gas Pressure Washer

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The Karcher G2700 2700 PSI / 2.5 GPM Gas Power Pressure Washer is the most versatile gas-powered model we’ve ever seen. Weighs just 48.5 lbs., this is the lightest one in our comparison. The sturdy cart is well balanced, and the folding handle allows convenient and compact storage. It can easily fit any small garden shed. Because of its compact design and a reasonable price, this is a great gas pressure washer for light-duty and medium-duty projects around your home.

If you never heard of Karcher, here is what you should know. Karcher is a German family-owned company that operates worldwide and is known for its high-pressure cleaners, floor care equipment, parts cleaning systems, wash water treatment, military decontamination equipment and window vacuum cleaners. Karcher makes some of the best electric and gas pressure washers in the world and they are very stable. Karcher is also the primary supplier of cleaning systems to both NATO and the US Military.

5. Briggs & Stratton 20545 2200PSI / 1.9GPM Gas Pressure Washer – Best Gas Pressure Washer for Light-Duty Projects

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Briggs & Stratton is known for quality power equipment, and this unit is no exception. The Briggs & Stratton 20545 2200PSI / 1.9GPM Gas Pressure Washer is one of the best gas-powered pressure washers for light-duty outdoor cleaning projects such as washing cars, trucks, siding, and patios. It is very stable and has enough weight to not topple when dragging the hose around, but light enough to handle with ease.

The Briggs & Stratton 550e Series OHV Engine is compact, lightweight and simple to operate. It is equipped with a Prime ‘N Pull Easy starting system to offer quick starts and smooth performance. With reduced vibration and improved, quieter sound, this engine is easy to use and durable.


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