How to Increase GPM on Pressure Washer

If you own a pressure washer, you know the satisfaction of seeing your surfaces become spotless in just minutes. However, as time passes, you may notice a decrease in its GPM (gallons per minute) flow rate. This can be frustrating when you have a big cleaning job to tackle. Luckily, there are a few simple ways to increase your pressure washer’s GPM and get back to tackling tough grime and dirt.

To increase GPM on a pressure washer, you can use a nozzle with a larger orifice size, upgrade the pump, or use a larger hose. Regular maintenance, including cleaning or replacing the inlet filter and inspecting the hoses and fittings for leaks, can also improve performance.

In this blog post, we’ll explore some effective tips to help you increase the GPM on your pressure washer and get the most out of your cleaning experience.

Understanding GPM

Understanding GPM

When it comes to pressure washing, having a high GPM (gallons per minute) is just as important as having high PSI (pounds per square inch). GPM refers to the amount of water flow that a pressure washer can produce in one minute, and it plays a crucial role in determining the effectiveness of your cleaning. Understanding GPM and how it affects your pressure washing is key to achieving the best results possible.

Definition and calculation of GPM

GPM stands for Gallons per Minute and is a unit of measurement used to determine the flow rate of liquid in a pressure washer. It is calculated by dividing the volume of liquid passing through a given point by the time it takes to pass.

In the context of a pressure washer, GPM is a crucial factor as it determines the cleaning power and speed of the machine. Therefore, it is essential to understand how GPM is calculated and how it affects the overall performance of the pressure washer.

Factors that affect GPM

Factors that affect GPM (gallons per minute) on a pressure washer include the size of the water supply hose, the diameter of the pressure washer hose, the pressure rating of the pump, and the nozzle size. Increasing any of these factors will result in a higher GPM output.

However, note that increasing the GPM too much can overload the pump and potentially cause damage. Find the right balance between GPM and PSI (pounds per square inch) for optimal cleaning power.

Importance of selecting the right nozzle for GPM

The right nozzle selection is crucial in increasing the GPM (gallons per minute) of a pressure washer. Choosing the wrong nozzle size can result in a lower GPM output, leading to ineffective cleaning.

A smaller nozzle restricts the water flow, while a larger nozzle may not provide enough pressure to clean the surface thoroughly. Therefore, it’s essential to select the appropriate nozzle size based on the pressure washer’s GPM rating to achieve optimal cleaning performance.

Tips for increasing GPM

Tips for increasing GPM

Achieving a high GPM output can be a challenging task, especially if you don’t know the right techniques. Following are some valuable tips on how to increase GPM on your pressure washer and get the most out of your cleaning experience. From adjusting your nozzle size to choosing the right pump, we’ve got you covered.

Adjusting the pressure washer engine and pump

To increase the GPM (gallons per minute) of a pressure washer, one important factor is adjusting the engine and pump.

This can be achieved by optimizing the RPM (revolutions per minute) of the engine, increasing the diameter of the pump’s inlet and outlet valves, and ensuring that the pump is properly lubricated. Using a larger diameter hose and nozzle can also help increase the GPM.

Proper maintenance and regular cleaning of the pressure washer can also contribute to its optimal performance.

Checking for clogged hoses or filters

One important tip for increasing GPM (gallons per minute) on a pressure washer is to regularly check for clogged hoses or filters. These blockages can significantly reduce the flow rate of water, ultimately reducing the effectiveness of the pressure washer.

By regularly inspecting and cleaning these components, you can ensure that your pressure washer is operating at its maximum potential and delivering the highest possible GPM.

Choosing the right nozzle size

Choosing the right nozzle size is essential in increasing GPM (Gallons Per Minute) on a pressure washer. A nozzle with a larger orifice size allows more water to flow through, resulting in a higher GPM output.

However, match the nozzle size to the pressure washer’s PSI (Pounds per Square Inch) rating to avoid damaging the equipment. It’s recommended to consult the manufacturer’s specifications or a nozzle size chart to determine the appropriate size for your pressure washer.

Using a larger diameter hose

Using a larger diameter hose can increase the GPM (gallons per minute) output of a pressure washer. This is because a larger hose allows more water to flow through it, resulting in a higher GPM.

However, make sure that the pressure washer is compatible with a larger diameter hose before making the switch. Using a larger diameter hose may require adjustments to the pressure washer’s settings to ensure optimal performance.

Upgrading to a higher GPM pressure washer

Upgrading to a higher GPM pressure washer can help increase the cleaning efficiency of your pressure washer. A higher GPM means a higher water flow rate, which can help you cover more surface area in less time.

However, choose the right pressure washer for your needs and to consider the PSI as well, as both factors work together to create the ideal cleaning power. Upgrading to a higher GPM pressure washer may require investing in a larger water source or upgrading your plumbing to handle the increased water flow.

Maintenance and care

Maintenance and care

Neglecting routine maintenance and failing to take proper care of your pressure washer can lead to a decrease in its performance and a shorter lifespan. Following are some essential tips and tricks for maintaining and caring for your pressure washer, which will ultimately help you to increase its GPM and improve its overall performance.

Regular cleaning and maintenance of pressure washer parts

Regular cleaning and maintenance of pressure washer parts is crucial to ensure optimal performance and increase GPM (gallons per minute). Neglecting maintenance can result in clogged nozzles, worn-out seals, and damaged pumps, leading to decreased GPM and pressure.

It is recommended to clean the spray wand, nozzles, and filters after every use and to check the oil levels, belts, and hoses before each use.

Proper storage, winterization, and periodic maintenance, such as changing oil and spark plugs, can also prolong the life of your pressure washer and maintain its GPM.

Avoiding damage to the pressure washer

When using a pressure washer, take precautions to avoid damaging the machine. To prevent damage, always use the appropriate nozzle and avoid using too much pressure on delicate surfaces.

Be sure to check the water supply for any debris or contaminants before using the pressure washer. Regular maintenance, such as cleaning and inspecting the machine, can also help prevent damage and ensure optimal performance.

Storing the pressure washer correctly

Proper storage of a pressure washer is essential for maintaining its performance and longevity. To store a pressure washer correctly, you should first clean it thoroughly and remove any leftover water from the pump and hoses.

It’s recommended to store the pressure washer in a dry and well-ventilated area to prevent corrosion and rust. You should also store it in an upright position to avoid any oil leakage. Moreover, you can consider using a protective cover to shield the pressure washer from dust and debris.


In conclusion, GPM or gallons per minute is a crucial factor to consider when it comes to pressure washers. It determines the cleaning power of the machine and the amount of water it can deliver in a given amount of time. The higher the GPM, the faster and more efficiently the pressure washer can clean.

To increase the GPM of your pressure washer, you can follow several tips, including checking and upgrading the water supply, using a larger diameter hose, selecting the appropriate nozzle size, and maintaining the machine properly.

By increasing the GPM of your pressure washer, you can enjoy several benefits, such as faster cleaning, better results, and reduced cleaning time. Moreover, a high GPM pressure washer can help you save water and energy, making it an eco-friendly option.

In summary, increasing the GPM of your pressure washer can significantly enhance its performance and cleaning capabilities. By implementing the tips mentioned above and choosing a high GPM pressure washer, you can ensure a more efficient and effective cleaning experience.

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Andrew Joseph
Andrew Joseph

Introducing Andrew Joseph, a pressure washing expert with 15 years of experience in residential, commercial, and industrial projects. Andrew shares his vast knowledge through insightful blog posts, offering valuable tips and best practices for optimal cleaning results. His passion for educating others, combined with his extensive expertise, makes Andrew an indispensable resource for those looking to master the art of pressure washing.