Good psi for pressure washer

What is a Good psi for pressure washer? The pressure put out by a power washer is measured in PSI (pounds per square inch), and the PSI requirements can vary based on what you’re aiming to clean.

For example, it’ll take a lot less pressure to clean dust and salt from your vehicle than it will take to clean oil stains from your garage floor.

Another factor that’s equally as important, but not often considered, is the gallons per minute rating (GPM). This measures how much water your pressure washer puts out per minute, and more water equals faster cleaning.

Good psi for pressure washer

Learning how much pressure is required to successfully clean different surfaces, materials, or objects will help you determine what size pressure washer you would best benefit from.

Remember, if you’re never going to exceed 2500 PSI, then you can save some money by choosing a 2600 PSI pressure washer over a 3000 or 4000 PSI pressure washer. The added power might make you feel like a stud, but why pay for it if you’ll never use it?

Also, knowing what’s required to complete different tasks will help ensure you select a power washer that’s powerful enough for what you are cleaning.PSI Requirements Per Application

How Much Water Flow Does It Take?

While water pressure provides the power to break up stains and settled in the dirt, water volume is what flushes that broken up filth away.

Essentially, the more water that moves through your nozzle in a minute, the faster you’ll be able to clean. Greater GPM (gallons per minute) cleans quicker because there’s more flowing water present to lift and carry away the dirt.

Imagine shooting a squirt gun at a clump of dirt on your sidewalk. It’ll break it up, but the dirt will still be there. Now pour a five-gallon bucket of water on that dirt, and it washes away. If you can combine the pressure of the gun with the volume of the bucket, you’ll have a great cleaning tool.

Pressure washers allow you to do just that, combine high pressure with high volume to clean surfaces in record time. So don’t forget the GPM, because it plays a role that’s equally as important to that of PSI.GPM relation to Cleaning Time

Pressure washers are machines that us a high pressure water spray to remove dirt and grime from a variety of objects and surfaces. Using a pressure washer is one of the fastest and most effective ways to clean, especially if you are trying to avoid the use of chemicals. The amount of cleaning power that a pressure washer puts out be looked at in a couple of ways. The first is the flow rate, which is usually displayed in litres or gallons per minute. The second, which we’ll get into more deeply in a minute, is the amount of pressure that the machine can produce, generally measured in pounds per square inch (PSI).

There are so many different types of surfaces that you can clean with a pressure washer – they are very versatile machines. You do to pay attention to the pressure though, because they are so powerful that you can actually damage certain surfaces if you aren’t careful. Each application has its own optimal nozzle and pressure setting.

It is very important to know how much pressure is required to successfully clean different surfaces, materials, or objects. Knowing the required pressure will help you determine the size of a pressure washer that would be most effective for each tasks.

Pressure washers are applicable to many things. They were once limited to use only in big industries due to the high prices and the sizes of the pressure washer that were being produced then. No homeowners could afford to get the washer at the time because it is too big and very expensive. Today, pressure washers is now popular and accessible to almost everyone as many compact pressure washers that are light and cartable has been manufactured for the benefit of individuals. Home owners can now purchase pressure washers for a reasonable price, and comfortably transport and use it in their homes.

Pressure washers can be used by both industries and homeowners. The industrial use could be for de-icing planes, cleaning freight cars, sanitizing food processing equipments and so on. While homeowners can use it to clean their environments, vehicles and so on. Below are some different applications of pressure washers and their requirements.


You can use use pressure washer to clean your cars, trucks, buses etc. It is very effective and fast to clean stains and dirt on vehicles especially the wheel wells and undercarriage, where most dirt are found. Ensure you are not using a high-powered setting, so you don’t end up peeling off your car’s coat or paint. You can use the 1500 PSI to 2600 PSI for the washing of cars.


Pressure washer can also be used to wash wooden surfaces, such as decks, stairs, wooden fences, patios and so on. You should however have it at the back of your mind that you will need to apply low-pressure nozzle, because a high-pressure water jet will be too much and can end up striping finish from wood. The wood can also end up getting waterlogged, which could result to it getting rotten over time. You should also avoid applying detergent with high pressure washer when washing wooden surfaces to avoid the wood getting bend and rotten.


Pressure washers are commonly used for this purpose. Trash cans are susceptible to sticky dirts hanging around after emptying the bins. This remnant can be removed effectively by using pressure washer. Using hand to scrub the bin can be very difficult and unhealthy. In order to do this fast and efficiently without the fear of getting bacteria infection, it is best to use a pressure washer.


Our concrete driveways and garage floors get stained more often as a result of oil and fluid that leaks while driving in and out. They are very difficult to clean, but making use of a pressure washer can easily get rid of these stains. To clean out these oil and fluid stains, You will need to use a high pressure nozzle and detergent. The use of both will be very effective in removing all oil stains, leaving the driveway neat and sparkling.


As a boat owner, you need to understand that cleaning and maintaining a boat can somewhat be a very tedious task to do. Looking at the materials which most boats are made of, such as metal, wood, glass, and fiberglass, you will be needing something as strong and versatile as a pressure washer machine to clean all the dirts and stains that a boat could have. Pressure washers are most suitable for cleaning any type of surfaces. As far as I’m concerned, boat bottoms of marine growth such as barnacles and algae can be wiped out using a high pressure washer. You will be needing a pressure washer of over a 3000 or 4000 PSI to get the job done.


Lawn mowers and yard equipment are prone to getting dirty every time they are used. This is because grass and leaves get stuck up on this equipment most times when mowing. They however, deserve to get cleaned up once in a while after use. We can use pressure washer to get rid of all of the accumulated dirt and grass and keep them ready for use in the spring.


Using grill can be fun, but what is most annoying is having to clean it afterwards. After use, The grill is left with lots of grease and grime that is burned deep into the metal. This can be crazy annoying and extremely difficult to clean. With the invention of pressure washer, all those cleaning difficulties are no longer an issue. Cleaning of grill becomes easier for every users. To clean the grill with pressure washer, it is highly recommended to use a degreaser for about 5 minutes to dissolve the burnt grease on the grill. Then the pressure washer can be used to blast the grill and remove the difficult stains.You need to be extremely cautious when doing this. All electricity connections, propane tanks, gas line etc should be disconnected to avoid hazard.

What You Need to Know Before Buying a Pressure Washer

pressure washer buying guide

Pressure washers have come a long way. Over the last ten years the quality has increased as prices have become more affordable. The cleaning ability of a pressure washer is great, removing dirt, grime, and algae quickly, efficiently and effectively. A pressure washer can greatly increase your ability to maintain and clean your property and equipment giving it greater value. If your time is valuable, a pressure washer could be a good investment, but if you get the wrong machine, you will be frustrated and you could waste a lot of time and money.

The goal of this buying guide is to help you understand what a pressure washer does and what you need to look for when deciding to purchase one. If you’re ready to start shopping, check out the pressure washers at Or keep reading to learn more about the following:

  • How a Pressure Washer Works
  • Pressure Washer Pumps
  • Direct Drive or Belt Drive
  • Gas or Electric
  • Pressure Washer Accessories
  • Choosing the Right Pressure Washer

How a Pressure Washer Works

A pressure washer is actually a fairly simple piece of equipment. A motor or engine turns a pump, pushing water through an orifice (tip). The water accelerates as it goes through the small hole, much like a river flows faster in a narrow gorge, and that fast-moving water is very useful for blasting dirt and grime. The math is quite simple. Each time the pump turns over, a specific volume of water is pushed through the tip. The more water you push through the tip, the more pressure is developed, and therefore more power is required. The higher the pressure, the faster the water moves, and the harder it hits the dirt, removing it from the surface you want to clean.

What to Consider

The two most important considerations when buying a pressure washer are size, which determines how long it takes to do the job or how many jobs you can do in a day; and life expectancy, which determines how many hours of work you can do per dollar spent during the life of the machine.

Understanding Ratings

Here are some basic ratings:

Horse Power (HP)

This is how much power the engine or motor produces. This rating is important because it directly relates to how much pressure and volume the pump can produce.

Pounds Per Square Inch (PSI)

The pressure generated by a pressure washer is measured in pounds per square inch or PSI. Pressure contributes to the cleaning force.

Gallons Per Minute (GPM)

The water volume produced by a pressure washer is measured in gallons per minute or GPM. Volume also contributes to the cleaning force.

Cleaning Power Units (CPU)

Cleaning Power Units quantifies a pressure washer’s cleaning ability. To determine CPU, multiply GPM x PSI. The greater the CPU, the greater the ability the machine has for cleaning deeply and effectively.

Often consumers are so focused on the PSI rating of the machine, they do not consider the CPU. For example, a pressure washer may have a rating of 2,800 PSI and 2 GPM, giving it a CPU of 5,600. Another pressure washer is rated for 2,400 PSI and 4 GPM. That’s a CPU rating of 9,600. In this example the lower PSI machine has more than 40% greater cleaning power than the higher PSI machine. The result is that the 2,400 PSI machine will be able to clean an area 40% faster than the 2,800 PSI machine.

Now consider this: A garden hose typically provides 6 GPM at 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 surfaces. Trying to clean your driveway with your garden hose spray nozzle generating 200 CPU is fairly ineffective. However, if we take a mid-range pressure washer rated at 2.0 GPM and 2,500 PSI (5,000 CPU), the CPU rating represents a staggering 25 times increase over a typical garden hose spray nozzle.

A commercial pressure washer rated at 4 GPM and 4,000 PSI is an incredible 16,000 CPU. It is not difficult to see the difference in efficiency. However, this is all true within a range. If you have extremely high pressure and low volume, you can cut steel or concrete (water jet cutter), and if you have extremely high volume and low pressure, you have a river. Neither of these would be very good for cleaning your house or driveway.

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pressure washer buying guide
Pressure washer pumps have pistons and valves similar to a gas engine or an air compressor. On some pumps the pistons are driven by a wobble plate. On others, the pistons are driven by a crankshaft. Crankshaft-driven pumps are generally built better and will last longer.

Pressure Washer Pumps

This is the part of the pressure washer that receives water from your hose, and pumps it through a tip at high pressure. There are several common types of pumps that you will see in commercial and home-owner type machines. All pressure washer pumps have pistons and valves similar to a gas engine or an air compressor. On some pumps the pistons are driven by a plate on an angle (wobble plate), and in other cases the pistons are driven by a crankshaft. Crankshaft driven pumps are generally built better and will last longer.

Pressure washer pumps are equipped with bypass valves, so that when you let go of the trigger, or when the tip gets plugged, the water will bypass and go back to the inlet side of the pump. If left in this mode for longer than the manufacturer recommends, the water will get hot and cause damage to the pump. On a gas-powered pressure washer, the pump includes a thermal relief valve that dumps hot water into the bypass loop. Most bypass valves are adjustable so you can dial down the pressure when cleaning sensitive materials

Low-cost pressure washers have pumps with very low life expectancies—some as low as 60 – 100 hours. When buying a pressure washer, make sure you find out the life expectancy of the pump. If the information is unavailable, stay clear because it is very likely that the manufacturer does not want you to know how low it is.

Another very important factor to consider is parts availability. KMS Tools was a warranty/service centre for some low end brands, however lack of parts availability and unreliability of these machines were such a problem that we decided to no longer provide this service.

Before buying your machine, ask where you can get parts if you need them. KMS is often referred to by other retailers as a source for parts and repairs for numerous brands that are pretty much disposable. If you are buying a new machine for $200.00 or less, expect it to be a disposable machine that might last you only one season, and be prepared to spend a lot of time to get the job done.

pressure washer buying guide

Direct Drive or Belt Drive

The drive describes how the motor is connected to the pump. Direct-drive systems are most common. The pump is bolted directly to the motor or engine with a shaft coupler. Compared to a belt-drive system, direct drive requires fewer parts and space, resulting in a more compact design. Direct drive is also considerably more economical than an equivalently rated belt-drive machine.

Belt-drive systems are typically seen on industrial platforms. The pump on a belt-drive unit turns at a much slower speed. The belt absorbs vibration that would wear out a unit faster. Since the pump turns at a lower speed all the pistons and valves in the pump are larger. All this adds up to a cooler running machine that will last considerably longer than an equivalent direct drive version. However, there is slightly more maintenance and considerably more dollars involved (10 – 30% more). If you are using your pressure washer on the job, then you want to consider buying a belt-drive machine. However, an equivalent direct-drive machine will have the same performance for a lot less money.

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pressure washer buying guide

Gas Engine or Electric Motor

On a pressure washer, the engine or motor powers the pump. The more powerful the engine or motor (rated in HP), the greater the PSI and GPM the pump produces. Gas engines are typically designed to last between 300 and 3,000 hours. The motors on electric pressure washers usually last longer than the pumps.

Electric Motors

Electric motors are very low maintenance and fairly quiet. There is also no exhaust so they can be operated indoors or in poorly ventilated areas. A typical electric pressure washer that is 115 Volt and 15 Amps will be fairly light duty because it is built for the low-price market. The motor is not strong enough to generate much pressure or volume. While electric pressure washers are compact and usually portable, most jobs take longer with a light-duty electric pressure washer.

HP is rated differently on electric motors compared to gas engines. A typical low-price electric pressure washer is rated around 1 to 1-1/2 HP and would be equivalent to a 3 HP gas pressure washer. (Electric motor HP has to be doubled to equal gas engine HP.)

Heavy-duty electric pressure washers are available for applications where power is available and portability isn’t a factor, and exhaust from a gas engine would be a problem.

Gas Engines

Gas pressure washers are larger and heavier and mounted on a cart with wheels. Some are better balanced and easier to maneuver. Gas engines can produce more power and are a lot more mobile as they do not need to be plugged in to an electric power source. Since gas engines can be more powerful, the pump can generate considerably more PSI and GPM so that they can clean faster and deeper than any 115 Volt rated electric pressure washer could. However they do take a little more maintenance and cost more to operate. They must be used in well-ventilated areas because of the emission of carbon-monoxide fumes.

pressure washer buying guide

Pressure Washer Accessories

Without accessories, your pressure washer is fairly useless. It would be like having a drill without any drill bits.

Pressure Washer Hoses

You probably want a 50 ft length hose. If you go shorter, you will have to keep moving your machine. Make sure you get a quality hose with the proper PSI rating to match your machine. A poor quality hose will break down faster, is more susceptible to leaks and kinks, and will usually be less flexible and harder to work with.

Pressure Washer Wands and Tips

The wand includes a handle with a trigger valve, and different lengths and angles of wands are available for different applications. You can change the spray pattern by changing the tip at the end of the wand. Most pressure washers come with a selection of tips—from a very narrow spray to generate higher force at the tip for deeper cleaning to a wider spray that has less force but covers more area. Most tip sets also include a low pressure tip for applying cleaning solutions.

In addition to tips, other, very useful attachments are available:

Dirt Blasters

A dirt blaster or rotary nozzle attaches to the end of your wand. It has a very narrow spray that spins in a circular motion very rapidly. Dirt blasters are effective because they can quickly clean hard surfaces very well and, when used properly, avoids the tiger striping effect on your driveway that happens with conventional spray tips.

Extension/Telescoping Wands

For cleaning out-of-reach areas, look for an extension wand that’s adjustable up to 24 feet in some cases. Extension and telescoping wands are beneficial if you need to reach up high. They can save you from trying to pressure wash while standing on a ladder.

Gutter Cleaners

A gutter cleaner is a simple hooked extension that affixes to the end of your wand. It lets you get into your gutters to clean them out.


A Whirl-A-Way is an accessory that looks a little like a lawn mower and has two rotating nozzles inside. They are available in sizes from 12” to 24” and excel at cleaning large flat areas.

Hot Water Pressure Washers

Hot water pressure washers are commercial machines with built-in water heaters. The cleaning effect of the machines is considerably better than a cold water machine with comparable PSI and GPM because hot water simply cleans more effectively than cold water. Hot water pressure washers break down and remove dirt and grime faster than cold water pressure washers, and often eliminate the need for expensive chemicals. Do not feed hot water into a normal cold water pressure washer pump. The heat will damage seals and o-rings.


Detergents can greatly increase the speed of cleaning and help remove tough stains. Most pressure washers come equipped with a venturi tube that will draw in the detergent from a bottle or pail and add it to the water stream. The detergent should be first applied with a low pressure spray, given some time to do its work to break down the dirt, and then washed off with a normal high pressure spray.

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Choosing the Right Pressure Washer

When it comes right down to it, you need to buy a pressure washer that fits your application. There are many different types of pressure washers—from very low-end machines to extremely powerful industrial machines. Before you buy a machine you need to sit down and ask yourself these questions:

  • “How will I use a pressure washer?”
  • “How often will I use a pressure washer?”

If you are a home owner, you will probably use a pressure washer less than 50 hours per year. In this case getting a machine rated for 500 hours will last you up to 10 years if properly maintained. However, if you are using it on the job, you will want something rated for 2,000 hours or more. If time is important to you, buy as big a pressure washer as you can justify. A 13 HP gas pressure washer will clean your driveway about 10 times faster than a small electric unit. It will also last longer because it doesn’t have to run nearly as long to do the job. Finally, plan in advance what attachments you will want in the future and make sure that the pressure washer you buy has enough power to support them.

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