Best Generac Power Washer

Generac has a range of gas-powered pressure washers to cater for all types of use, from cleaning decks, patios, and vehicles to paint stripping and graffiti removal. With around ten different models, PSI ratings from 2500 up to 4200 and various GPM ratings, you might be wondering either A) what the hell we’re talking about or B) how you’re going to select the right model for your particular use!


That’s where we’re going to help as we’ve selected three of their top models across the range to cater for the most common jobs and completed a full review of each including their different specifications and what customers actually think about them. We’ve even throw in explanations of some of the pressure washing jargon as well as gone over some of the things to look for when comparing the units.

We expect you’re itching to get into it so let’s get started.

ModelGenerac 6922Generac 6602 One WashGenerac 6565
Picturegenerac washer 6922generac washer 66026565 washer
OverviewResidential model perfect for medium duty jobs around the house including cleaning vehicles, decks, fences, furniture and up to a limit, prepping a house for painting and cleaning driveways etc.More powerful residential washer with a power dial to easily adjust the PSI/flow rate through four different settings. Covers medium to heavy duty jobs right across the board.Very powerful and robust commercial grade pressure washer that would be best for heavy duty jobs including cleaning paths and driveways, construction and farm tasks plus use in an industrial setting.
Generac 4-cycle OHV Engine196cc212cc420cc with low oil shutdown
Maximum pressure (PSI)280031004200
Pressure control valve/dialNoYes – 4 position dialYes - Valve
Spray GunSoft grip ergonomicSoft grip ergonomicProfessional quality with adjustable side handle
High pressure hose25ft PVC 0.25in diameter30ft PVC 0.25in diameter50ft steel reinforced rubber. 0.375in diameter
Number of nozzles included4 (soap, 0, 25 and 40 degree spray)3 (soap, 0 and 25 degree spray)5 (soap,0,15,25,and 40 degree spray)
Wheels and tires10in Never Flat11in Never Flat12in Pneumatic
FrameWelded steel. UprightWelded steel. UprightWelded steel. Roll cage type.
Folding handleNoYesYes
Detergent injectionYes – onboard 0.5 gal tank. No drain plug.Yes – onboard 0.75 gal tank. With drain plug.Yes – siphon tube only
AssemblyYes – easy (30 mins)Yes – easy (30 mins)Yes - Very little (5 mins)
CARB CompliantYesNoNo
Warranty2-year residential2-year residential3-year commercial
Assembled depth (in.)24.220.634.5
Assembled height (in.)35.539.542.5
Folded height (in.)N/A2233
Assembled width (in.)18.92128.3
Machine weight (lb) 5768.5146.5
Fuel tank capacity (gallons)
Oil tank capacity (fl oz)202037

Introducing Generac

Founded in 1959, you would be forgiven for thinking that Generac is just a manufacturer of standby power and backup generators. This certainly was their core business back when the company started and continues as an important market for them to this day. But back in the 1990s, they utilized their knowledge of portable products and air cooled engines to start designing power washers and ended up capturing around 50% of the consumer market as well as registering patents that changed the pressure washing industry at the time.

That all stopped when they sold the portable product side of the business to concentrate on developing home standby generators, which is where they really made their name and continue to still innovate and dominate in that area.

Generac has since re-entered the portable generator market in 2008 and started making and selling power washers, more commonly known these days as pressure washers, again in 2011. Their washers have since become some of the most popular on the market today and for good reason. Much of the design and engineering is done in-house which allows them to keep very close control on specifications and production values, resulting in some of the highest customer ratings around for the pressure washer market.

What models have we selected?

As not all pressure washers are created equal, we wanted to provide models to suit most purposes including the following, which are listed in order of how much power a pressure washer would need to do them properly:

  • Vehicle and boat cleaning
  • Cleaning fences and decks
  • Washing down outdoor furniture
  • Cleaning dirt and grime off driveways and patios
  • Prepping a house for painting
  • Scrubbing mildew and mold of concrete
  • Cleaning construction and farm machinery
  • Commercial and industrial use

We’ve selected three models that cover the whole range of tasks and obviously overlap to some extent, these are:

generac washer 6922

Generac 6922 2,800 PSI – a residential model perfect for medium duty jobs around the house including cleaning vehicles, decks, fences, furniture and up to a limit, prepping a house for painting and cleaning driveways etc.

6602 washer

Generac 6602 OneWash 3,100 PSI – a powerful residential washer with a power dial to easily adjust the PSI/flow rate through four different settings. Covers medium to heavy duty jobs right across the board.

Generac 6565 4,200PSI – a powerful and robust commercial grade pressure washer that would be best for heavy duty jobs including cleaning paths and driveways, construction and farm tasks plus use in an industrial setting.

What are those PSI and GPM ratings all about?

These two ratings are possibly the most important when comparing different models of pressure cleaners and combined, they give us an indication of something called ‘cleaning power’ which is a good reference point.

PSI stand for pounds per square inch and is used to measure the pressure of the water that comes out of the machine. To get some idea, a garden hose will squirt the water out at about 50 PSI whilst a typical car wash operated by coins will usually be rated around 700 PSI. The pressure washers we are looking at range from 2800-4200 PSI so quite a difference!

GPM is the other important rating and this stands for gallons per minute. As you can probably guess this is used to measure the rate at which the water flows through the unit. It is important as a higher GPM means more water flowing through which in turn will mean you can work faster.

Think of it this way; the PSI provides the power to lift off dirt and grime whilst the GPM provides the speed at which the washer works.

Multiply them together and you get the washer’s cleaning power rating, which helps to compare different models from both the same and other manufacturers so you can tell with some degree of certainty how well they will perform. Of course, there’s more to it than that, the nozzles provided, the length of pressure hose, types of wand etc. all have their part to play as well. Each model also has a few unique features of its own which may or may not make a difference, but we will talk about that in each product review.

Pumps and Engines

All of our machines have an easy to start horizontal-shaft 4-cycle OHV engine made by Generac with a low-oil shutdown sensor. Mounting the engine this way means the pump unit can be placed higher up making it easier to access all the hose connections. The pumps themselves are all made by Anno Reverberi (AR) and are one of two types:

Axial pumps have pistons driven directly by the engine driveshaft that pumps the water through at pressure and is a type commonly used in residential pressure washers up to 3500 PSI.

The Triplex pump uses three pistons connected to a crankshaft for higher pressure and increased lifespan of thousands of hours with minimal maintenance. These pumps are more expensive and higher-grade so used mainly in commercial type pressure washers producing over 3000 PSI.

Note that all these models are built to take a cold-water feed only!

Hose, Spray Gun and Nozzles

All the washers have an ergonomic spray gun with cushion grip handles and an easy to pull trigger that helps to reduce fatigue. The nozzles are of the quick-connect, interchangeable variety and come in the industry standard color codes to denote how abrasive the spray pattern is (note that not every model has all of these):

  • Black – low-pressure nozzle used for dispensing liquid soap
  • White – 40-degree spray pattern for gentle cleaning
  • Green – 25-degree pattern for medium strength cleaning
  • Yellow – 15-degree spray pattern for high-pressure work
  • Red – zero-degree pencil spray for stubborn stains. Can be dangerous so handle with care!
  • They are all very easy to change, just a push and twist does it, with storage for each one supplied on the machine itself. There is also a holster on the side to take the spray lance when not in use.

Warranties on the Generac washers

The warranty on the two residential machines is for two years and during the first year covers all components from defects in materials or workmanship. During the second year, only the engine is covered. Commercial use is not covered at all.

The commercial grade 6565 has a three-year warranty with all components covered for two years and just the engine for the third year.


We cannot stress enough how important it is to take the time to read through the manual from end to end for any pressure washer. If you don’t follow the instructions carefully, you could easily end up with a costly repair that’s not covered by the warranty. There is a strong suspicion that many of the problems encountered and which may result in a one-star review could have been avoided by doing things right. Not all of them of course, there are bound to be some issues even with the best machines. Things to watch out for that could cause you trouble include:

  • Using the right grade and type of fuel
  • Correct sequence of operation
  • How to fill and check the oil
  • Regular maintenance and checks

Follow the guidelines for all those things and we think you will get many years of trouble-free use out of your Generac pressure washer.

Individual Product Reviews

Now that we’ve covered some of the basics, we’re going to take a look at the individual specification for each machine so that you can see how they stack up against each other.

Generac 6922 2,800 PSI

The Generac 6922 is their low to mid-range residential model which provides 6720 units of cleaning power making it ideal for cleaning vehicles, patios, decks, fences and garden furniture. It’s also the lightest of our models so there should be no problem moving this around. The simple controls and user-friendly design are geared towards making this one easy to assemble, connect hoses and generally use for your light to medium duty jobs around the home.

generac washer 6922

Engine and washing power

The horizontal shaft 196cc engine in the 6922 delivers around 6hp and provides great performance for what is essentially a budget gas powered model according to its price. Together with the axial pump fitted to this model it provides a maximum of 2800 PSI of water pressure at a flow rate of 2.4GPM.

As this is a 4-cycle engine it uses unleaded gas (minimum rating 87 octane) and not the gas/oil mix used in 2-cycle machines. The fuel tank has a 0.8 gallon capacity and will last you around an hour of fairly constant use according to reviews. Note the tank is not translucent and does not have a fuel level window so the only way to tell if it needs topping up is by taking the cap off. The engine oil is held in a separate tank which takes 20oz of oil, there is a bottle included with the machine so no need to buy some initially.

How easy is the 6922 to assemble?

Assembly is simple on this machine, mainly just attaching the handle to the welded steel frame, then connecting the high-pressure hose and spray gun. It’s very easy to do and will take you just 15 to 20 minutes.

Apart from adding fuel, filling up the oil tank and connecting up the water hose, that’s it, so you should be up and running in around 30 minutes.

Detergent tank and nozzles

This model has an onboard 0.5 gallon detergent tank so that you can add in some detergent when spraying with the black nozzle. The only let down with this is that it doesn’t have a drain plug so it’s difficult to get any unused liquid out. You also have to be careful to make sure the siphon tube doesn’t touch the exhaust muffler as it will melt. One tip we found is to just tie wrap it to the frame so it’s out of the way, perhaps Generac should provide a clip specifically for that purpose!

There are four nozzles provided with this model; red, green, white and black. See the section earlier on the different uses for each one.

You will also find on the back of the handlebar panel a wire hook to store the 25-foot-long, 0.25-inch diameter high-pressure hose. The hose is made of PVC and will need uncoiling before use otherwise it tends to get tangled up, like most plastic type hoses.

Wheels, size, and weight

This model has 10” ‘never flat’ tires that make it very stable to wheel around and park wherever you need it. At 57lb it’s not too heavy to maneuver either.

When assembled the washer measures approximately 35 inches high by 19 inches wide and 24 inches deep. It doesn’t fold down into a smaller unit for storage so this is the area you will need for that as well.

What the users think and final thoughts

Overall the reviews for the 6922 are very positive with few complaints. Looking through any reviews highlighting problems there do not seem to be any patterns of defective equipment as such, just isolated cases of either the engine not starting or pump issues.

Summing up, this machine is great value and is the one most homeowners should go for who require a pressure washer for the usual range of light to medium duty jobs around the home and garden.

Just to recap, here are the main features again and a list of the specs for easy reference.

Main Features

  • Generac 196cc OHV engine delivers around 6HP for great performance
  • Produces a maximum 2,800 PSI pressure at 2.4 GPM
  • Strong welded steel frame
  • Horizontally mounted axial cam pump makes it easier to attach hoses
  • Ergonomic spray gun with easy-to-pull trigger and a cushioned grip helps to reduce fatigue when using for a long time
  • Integrated 0.5 Gal detergent tank makes it easy to add soap into the spray when using the black nozzle
  • 25 ft. long high-pressure hose which connects at the rear of the spray gun for ease of use
  • 4 quick-change nozzle tips included: 0°, 25°,40° and soap
  • Some assembly required
  • CARB compliant
  • 2-year warranty


  • Assembled Depth (in.) 24.2
  • Assembled Height (in.) 35.5
  • Assembled Width (in.) 18.9
  • Hose Diameter (in.) 0.25
  • Hose length (ft.) 25
  • Wheel Diameter (in.) 10
  • Machine Weight (lb) 57
  • Maximum Pressure (PSI) 2800
  • Fuel Tank Capacity (gallons) 0.8

Generac 6602 OneWash 3,100 PSI

The 6602 OneWash power washer is a step up from the 6922 in terms of features, power and of course price. The big feature on this model is the power dial which allows the user to select four different pressure and flow settings for different jobs. Hence the marketing blurb for this model which bills it as four machines in one and actually is not far from the truth.

6602 washer

The cleaning power for this unit comes in at 8680 cleaning units at the maximum setting, which is very respectable for a mid-range device. With that adjustable dial, this washer can do everything from vehicle cleaning to removing tough dirt off bricks and concrete. It is more expensive than our first model, but not by much and is well worth it in our opinion.

We will take a look now at how this compares to the 6922 so if you are jumping in at this point, you might want to read the details on that model to get some context.

Engine and washing power

The engine in this model is one of the most powerful in its class, 212cc developing approximately 6.5hp. The 6602 has an axial pump like the previous model and is rated at 3100 PSI / 2.8 GPM for a quick and powerful wash.

As mentioned above, the cleaning power of this washer can be set by a dial on the top of the unit. This has four settings:

  • Car – best for cleaning boats, cars, RVs etc.
  • House – use for cleaning sidings etc. around the house
  • Wood fence – good for cleaning fences and decking
  • Brick – best setting for cleaning brick, concrete, and masonry

You should be able to find a setting to complete most residential jobs without too much trouble using this dial making the 6602 handy for most tasks.

How easy is the 6602 to assemble?

Assembly is very similar to the lower powered model above, just assemble and attach the handle plus the high-pressure hose to the strong steel frame. On this model, the handle is actually foldable which helps reduce the height needed for storage.

You just need to fill the oil tank, add gas and connect the water supply hose and it’s ready to go.

Detergent tank and nozzles

Unlike the previous model, the 0.75 gallon detergent tank provided with the OneWash has a drain plug to make it easy to empty out any unused detergent, a big improvement.

There are only three nozzles provided with this model; red, green and black. The section earlier on nozzles provides information on what to use them for.

You will also find a wire hook on the back of the handlebar panel to store the 0.25-inch diameter high-pressure PVC hose which on this model is 30-foot-long. Like other plastic or vinyl hoses, it’s important to straighten this out before use to avoid it twisting.

Wheels, size, and weight

This model has 11” wheels with never flat tires which help to make moving the washer around easy even with its heavier 68.5lb weight. That’s actually not too bad for a pressure washer that can do four jobs in one.

Assembled and with the handle up, the unit measures 39.5 inches high by 21 inches wide and 20 inches long. With the handle folded down for storage, the height reduces to about 22 inches.

What the users think and final thoughts

Overall the reviews for the 6602 are a little mixed but researching them it appears most of the problems are not with the performance of the machine but relate to either shipping issues or a problem with the On/Off switch. It looks as though most of the issues with the switch were on machines bought in 2014/2015 and were fixed by the owners pushing the connectors back on. Other than that, many users are very happy with how the machine works with only a few isolated starting problems.

Summing up, this model provides great value with the versatility of the power dial switch making it capable of tackling most light to heavy duty jobs around the house and garden. If you need a more powerful machine than the 6922 but at an affordable price, then this is the model to go for.

Here is a reminder of the main features and a list of the specs for easy reference.

Main features

  • Four power settings with variable-pressure technology makes this ideal for a wide range of tasks
  • Powerful Generac 212cc OHV engine is one of the best in its class
  • Soft-grip handle on the spray gun for comfortable use
  • Inverted easy-pull trigger reduces user fatigue
  • Spray gun has rear hose connection for a better balance
  • All controls are in one location on a consolidated control panel
  • Horizontal axial cam pump placed high up for easier hose connections
  • Footrest stabilizes machine during starting
  • Welded steel frame
  • 11-inch wheels with never flat solid tires
  • Handle folds for compact storage
  • Integrated 0.75 Gal detergent tank with drain plug
  • 30 ft. long high-pressure hose
  • 3 quick-change nozzle tips included: 0°, 25°, and soap
  • Some assembly required
  • Not CARB compliant
  • 2-year warranty

Generac 6565 4,200 PSI

The 6565 is the only model in our lineup which can be classed as a true commercial machine, which is not surprising given its huge cleaning power rating of 16,800 cleaning units! This model handles everything you can throw at it although you will need to be careful using it on certain surfaces such as vehicle paintwork.

It’s going to be best at home in a farm, construction or industrial setting although if you have some very tough jobs to do around the home it would be well worth considering. That extra power comes at a price, though, with this model costing around twice as much as the 6602 OneWash.

Engine and washing power

As you might expect, this has the most powerful engine of the three, a Generac 420cc version with around 12hp of power, that can, in fact, top many other commercial washers out there. This model has the much more robust and longer life triplex pump as well that puts out 4200 PSI at a flow rate of a staggering 4 GPM. The pump is professional quality with ceramic coated pistons for durability.

Although the 6565 doesn’t have a power dial like the OneWash machines, it does have a pressure control valve that lets you reduce the pressure when washing things like vehicles and boats. That helps make this machine more versatile than it first seems as reportedly you can vary it through any setting right down to around 1500 PSI although the manual does not specify the actual rating.

The gas tank on this model is a lot larger at 1.5 gallons, as is the oil capacity, taking 37oz of oil to fill the tank. Additionally, the pump also has its own oil reserve that will need checking on set up and when in use.

How much assembly is required on the 6565?

Assembly is very simple, you just need to pull the handle up from its folded position and attach the hose hook so ten minutes at the most. The handle can easily be folded back down again for easy storage or transporting.

After that, attach the high-pressure hose and spray gun, add engine oil and check the pump oil, then fuel up and it’s ready to go.

Detergent tank, nozzles and the pressure hose

There is no actual detergent tank on this model but a siphon hose (supplied) can be connected and dropped into a suitable container placed next to the washer when in use if you need to inject some detergent.

With the commercial model, you get all five of the quick-connect nozzles to cover all uses. See the section near the beginning for the different colors and what they mean.

The high-pressure hose supplied is much tougher than on the cheaper models to cope with that 4200 PSI. It’s made from steel reinforced rubber with a 3/8” diameter and measures 50ft in length.

Wheels, size, and weight

The wheels on this model are 12” with pneumatic tires so they can handle all sorts of rough terrain. You will need those easy rolling tires as the weight of this machine is a heavy 146lb which is a lot to move around. This model features a strong welded steel roll cage type frame for extra protection as well which adds to the weight.

Size wise, when the handle is folded down for storage it measures around 33 inches high by 28 inches wide and 35 inches long. With the handle up for use, the height increases to 42.5 inches.

What the users think and final thoughts

There really are not that many bad things said about the Generac 6565, just a few isolated cases of problems starting, which on this model having such a high PSI could be to do with not following the correct procedure. Another tip we found is to turn the pressure valve down to its minimum setting when starting as that also helps to make pulling the cord easier. Overall users are very happy with their commercial grade washer.

In summary, this model may be expensive but if you need something that can handle any task, no matter how tough the dirt or grime, then this beast is it. This is the only model in our selection that can also clean the second story of a house from the ground, although you may need to look at some different nozzles to get the best results.

For an easy reference, here’s a summary of the main features and specifications:

Main features

  • 420cc Generac horizontal-shaft engine with low oil shutdown designed for a long life and high performance
  • Commercial grade triplex pump with ceramic coated pistons for longer working life
  • Complete control over water pressure through the pressure control valve
  • Generac spray gun is professional quality and has adjustable side handle for precise control
  • Rear hose connection on spray handle for maximum convenience and balance
  • 50ft of steel reinforced 3/8 in. rubber hose included
  • All 5 quick-click nozzle tips included (see earlier section)
  • 12 in. pneumatic wheels for all terrain capability and shock absorption
  • Strong roll-bar style frame for extra protection. Made from welded steel
  • Handle folds for compact storage
  • Detergent siphon hose included
  • Very little assembly required
  • Not CARB compliant
  • 3-year commercial warranty


  • Assembled Depth (in.) 34.5
  • Assembled Height (in.) 42.5
  • Assembled Width (in.) 28.3
  • Hose Diameter (in.) 0.375
  • Hose length (ft.) 50
  • Wheel Diameter (in.) 12
  • Machine Weight (lb) 146.5
  • Maximum Pressure (PSI) 4200
  • Fuel Tank Capacity (gallons) 1.5
  • Oil Tank (oz) 37


We hope you have now got enough information to make an informed choice of the Generac pressure washer best suited to you. If you have found the one you want, we recommend clicking below to check out the best deals on all these machines on Amazon.

Generac 6922

generac washer 6922

Generac 6602

6602 washer

Generac 6565

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