High-quality petrol pressure washers are among the most powerful pressure washers available on the market. In addition, models with a suction function can be used almost anywhere.
The only alternative in this power class are three-phase models, which inevitably require a power connection.
In this article, you will learn everything you need to know about buying a pressure washer with a petrol engine. In addition, we will give recommendations on which features should be available from which price range.
Top 10 Best Petrol Pressure Washers
Recommended petrol pressure washers
Recommended features:
- Pressure regulation
- Hose reel
- Water intake
- Detergent suction
- Min £400 purchase price
As petrol pressure washers can often build up very high pressures, a pressure regulator is recommended. Without it, it would not be possible to clean sensitive surfaces such as car paintwork or wooden decking.
Furthermore, in our opinion, only models with a purchase price of £400 or more are worthwhile. Since below the price of £400 there are often only models with poor durability and workmanship.
A water intake is also practical, as it allows you to operate the pressure washer completely self-sufficiently with a water tank or water source.
In addition, a detergent suction would be desirable, as this would allow you to clean even stubborn dirt with low pressures. A hose reel is also recommended for convenient use of the device.
Best Petrol Pressure Washers
Hyundai HYW4000P Petrol Pressure Washer Portable 420CC 14 HP 4-Stroke Engine 4000 Psi
£949.99
Features
- Powered by a Hyundai 420cc 4-stroke unleaded petrol engine: Provides easy starting, low emissions and reliable running in all weathers
- Annovi Reverberi (AR) pump producing 4000psi: For longer life as well as outstanding performance and reliability
- Low oil shutdown: Prevents engine damage due to lack of lubricant . Portable pressure washer: Fitted with puncture-proof wheels for easy mobility
- Supplied with range of nozzles, trigger gun, lance and extra-long 15m hose: Get started straight out of the box. Range of uses: Can be mains cold water or gravity-fed
- Peace of mind: 3 year Hyundai warranty* / 1 year commercial warranty* (terms apply)
Wilks Genuine USA TX750i Petrol Pressure Washer - 8.0HP 3950Psi / 272Bar
Features
- 12 months warranty and free customer service team on hand to assist with any queries that you may occur. Our goal is to resolve any problem that might arise.
- Easy to use, the jet washer can be stored in the trunk of the car or on your boat. Plug it into a faucet or barrel to instantly get sparkly clean with high pressure.
- Included five attach nozzles, all with different cleaning functions; blasting, stripping, cleaning, washing and detergent application. It could help to clean almost anything.
- Produce ultra-high peak power of 3950psi / 272 bar, delivers the power you need to make short work of cleaning your car, driveway, paving, home, or decking.
- High quality robust materials, features an 8HP, 210cc four-stroke engine with stubborn reliability and it’s fuel-efficient so you can keep cleaning for longer between refills.
Wilks Genuine USA TX625 Petrol Pressure Washer - 7.0HP 3950psi / 272Bar
Features
- 12 month warranty and free to call UK based technical support line
- Super convenient usability, simply put it in the boot of your car or on board your boat and this tap or barrel fed wonder will give you high power cleaning in an instant
- Includes five "Snap in" ceramic nozzles, each one gives you a unique cleaning function
- Producing ultra high peak power of 3950psi, perfect for cleaning your car, driveway, paving, home, decking and more
- Features a 7hp 210cc four-stroke engine with stubborn reliability and it’s fuel-efficient so you can keep cleaning for longer between refills
SIMPSON Cleaning CM60912 Clean Machine Gas Pressure Washer Powered by Simpson, 2400 PSI at 2.0 GPM
Features
- 149cc SIMPSON OHV engine with large recoil for easy starting
- Maintenance-free OEM Technologies axial cam pump
- ¼’ x 25’ High pressure hose is highly flexible, non-marring and kink resistant
- Ergonomic spray gun designed for comfort and control; Gun:Threaded M22 connection
- Three spray nozzles; 0-degree, 25-degree and soap and on-Board detergent tank
Wilks Genuine USA TX750 Petrol Pressure Washer - 8.0HP 3950 psi / 272 Bar
Features
- 12 months warranty and free customer service team on hand to assist with any queries that you may occur. Our goal is to resolve any problem that might arise.
- Easy to use, the jet washer can be stored in the trunk of the car or on your boat. Plug it into a faucet or barrel to instantly get sparkly clean with high pressure.
- Included five attach nozzles, all with different cleaning functions; blasting, stripping, cleaning, washing and detergent application. It could help to clean almost anything.
- Produce ultra-high peak power of 3950psi / 272 bar, delivers the power you need to make short work of cleaning your car, driveway, paving, home, or decking.
- High quality robust materials, features an 8HP, 210cc four-stroke engine with stubborn reliability and it’s fuel-efficient so you can keep cleaning for longer between refills.
Wilks-USA TX850 Petrol Pressure Washer - 15HP 4800psi / 331 Bar
Features
- 12 month warranty and free to call UK based technical support line
- Undoubtedly the market leader in the “big pressure washer” category with unrivalled power and features
- Massive 4800psi, making this washer the powerful in its class, reducing working time by up to 75% over smaller units
- Features a 15hp four-stroke engine with stubborn reliability and it’s fuel-efficient so you can keep cleaning for longer between refills
- 20 Metre commercial wire braided pressure hose, ultra-durable and allows you a massive reach without having to constantly move the machine whilst maintaining that huge pressure
P1PE Petrol Pressure Washer P4200PWT 4200psi / 290bar, Orange
£719.10
Features
- Commercial grade 420cc / 14hp Hyundai engine. High quality Annovi Reverberi (AR) Triplex Pump producing 4200psi / 290bar.
- Heavy duty powder coated tubular steel frame with soft grip foldable handle. Puncture proof 11.5” tyres.
- Hyundai IC4200 Recoil start engine. Low oil shutdown, to prevents engine damage due to lack of lubricant.
- Accessories include 15m hose, quick connection trigger gun, high pressure lance, and selection of nozzles. Covered by P1PE 2 year warranty. Full UK service and parts operation to maintain your pressure washer for years to come.
RocwooD Petrol Pressure Washer 3950 PSI 7HP 10 Litre High Power Jet FREE Oil
Features
- RocwooD 3950 PSI 7HP 10 litre PM petrol high power pressure jet washer. Plus a free 600ml bottle of SAE30 oil. One of the best value for money pressure washers on the market.
- Petrol pressure washer, Max Pressure: 3950PSI, 7 HP, 4 Stroke OHV Petrol Engine With Commercial Grade Crankshaft and Camshaft. 12 month domestic use warranty.
- Commercial grade direct drive brass cylinder axial pump with thermal relief valve. 10 metre high pressure hose with high pressure spray gun. 5 x quick connector jets (0, 15, 25, 40 and Low Pressure Chemical Jets).
- Adjustable pressure. Low pressure detergent injector. 2 metre water input hose with filter. 1 metre chemical input hose with filter. 8" rubber wheels.
- This pressure washer can have a water supply from an outside tap, or it can draw water from another water source such as a bucket, or pond, water butt etc.
Briggs & Stratton 020739 ELITE 3200Q Petrol Pressure Washer with Quiet Sense Technology 3200 max PSI/220 Bar - 875EXi Series 190 cc Engine
£509.10
Features
- Briggs & Stratton 875EXi Series engine / 190cc
- Maximum water pressure of 220 Bar with a flow rate of 612 litres per hour
- Including 4 Quick Connect spray tips: 0°, 15°, 40°, Soap
- Detergent Injection System
- Quiet Sense Technology makes the pressure washer's engine idle down automatically when the spray gun trigger is released for quieter operation
Hyundai 4000psi Petrol Jet Wash 420cc 15L/min Petrol Pressure Washer & 20" / 51cm Flat Surface Cleaner & 3 Year warranty
Features
- Time-saving cleaning bundle: Complete pressure washing tasks and clean flat surfaces quickly and evenly
- Pressure washer with a Hyundai 420cc 4-stroke petrol engine: Provides easy starting, low emissions and reliable running
- HYW4000P has Annovi Reverberi (AR) pump producing 4000psi For longer life as well as outstanding performance and reliability
- Whirlaway with large 20" stainless steel head: Prevents zebra-striping and streaking for a perfect finish
- Peace of mind: 3 year home-use warranty* / 1 year commercial warranty* on the HYW4000P and 1 year warranty* on the Whirlaway
Recommendations for different price ranges
450 l/h
Pressure regulating nozzles
Large wheels Water suction
min. 700 l/h
Pressure regulation
Hose reel
Water suction
Detergent suction
min. 800 l/h
Pressure regulation
Hose reel
Water suction
Detergent suction
Brass cylinder head
The most important features briefly explained:
Pressure (bar) / Working pressure / Maximum pressure
The water pressure, which is given in bar, is a quantity that indicates the strength of the water jet. However, a high cleaning performance can only be achieved if the flow rate is dimensioned in relation to the pressure.
If the pressure is too high, the water jet would dissolve into steam after a few centimetres. The water pressure is specified by many manufacturers as the maximum pressure.
This is the pressure that the high-pressure pump reaches mathematically. However, since this pressure is lower in reality, there is a second parameter that indicates the actual value: The working pressure.
The working pressure indicates the pressure that is applied after all attachments, excluding the hose and the high-pressure lance. It is not determined by calculation, but is measured in real terms. It is often 20% lower than the maximum pressure.
Delivery rate (l/min) / water volume
Inexpensive high-pressure cleaners often have the same pressure as more expensive models. The question is justified why one should choose an expensive model. After all, the cleaning performance is supposedly the same.
As always, the devil is in the detail. For the actual cleaning performance, the flow rate is much more decisive than the pressure. You can compare it with a waterfall and a water pistol. The water pistol has the higher pressure and can therefore “shoot” the water over a longer distance, but the waterfall has a much higher force.
Detergent tank / detergent intake
If the high-pressure cleaner has a detergent tank / detergent suction, you can decompose the dirt with solvent at the same time as high-pressure cleaning. This saves you the extra step of dissolving the dirt with cleaning agent before high-pressure cleaning.
The advantage of an integrated detergent tank compared to the detergent suction is that you do not have to carry an extra detergent canister with you.
Volume
As with all technical devices, the volume is given in dB. At a noise level of 80 dB, the use of hearing protection is recommended. At a noise level of 85 dB, hearing protection must be worn, as permanent damage to the hearing is caused at this volume.
What’s the deal with the clip-on nozzles?
Attachable nozzles are the cheapest way to adjust the pressure. Each clip-on nozzle has a different diameter and thus increases or decreases the pressure of the water jet. With a larger diameter, the pressure decreases and with a smaller diameter, it increases.
However, with these clip-on nozzle solutions, you can never adjust the pressure exactly. Therefore, it is not recommended to clean sensitive surfaces with such clip-on nozzles.
Initial start-up
Before using the machine for the first time, be sure to read the operating instructions. Do-it-yourselfers often completely ignore this well-intentioned advice: “After all, a man doesn’t need to read an instruction manual, right?”. However, with a petrol pressure washer, this behaviour can lead to a defective unit.
Many petrol pressure washers are supplied “dry”. This means that you have to fill oil into the combustion engine before switching it on for the first time. Depending on the model, the pump must also be filled. In addition, a certain amount of oil is required, so you must not fill the components to the top with oil. You can find out exactly where and how much oil you need to fill in from the operating instructions.
Another detail are the so-called transport oil plugs. These are needed if the pump has already been filled with oil by the manufacturer. They prevent oil from leaking out during the often rough transport. These transport plugs must be replaced with a regular oil plug before initial operation.
In addition, not every oil / petrol may be used. Exactly which oil you should use depends on the manufacturer’s specifications and the prevailing outside temperature. With petrol, you often don’t need to worry about this with newer units. Older models, on the other hand, often need a special mixture. All this information can be found in the operating instructions.
Checklist before first use
- Read the operating instructions
- Oil filled in the pump & motor
- Used the correct oil
- The correct amount filled in
- Replaced trans port plug, if any
- Used the correct petrol
Maintenance of a petrol pressure washer
The maintenance of a petrol pressure washer differs from unit to unit. Therefore, it is important to read the operating instructions carefully. The manual will tell you how often the pressure washer needs to be serviced and what needs to be done at each service.
Often, normal maintenance consists of changing the oil, oil filter and air filter. More extensive maintenance usually also includes changing the spark plugs. You can either order the materials for maintenance directly from the manufacturer or buy them from a DIY store.
The oil and spark plugs are often standard models that can be bought at any large garden centre. However, if seals or similar need to be replaced, you usually have to ask the manufacturer.
Starting the petrol pressure washer
Starting a petrol pressure washer differs from unit to unit. The most common variant is to pull on a cord. Before pulling the cord, however, you should switch on the petrol supply and the choke.
This can be done using small levers on the unit. In addition, a general start switch (emergency stop switch) must often be switched on.
When the engine is running and has reached its normal operating temperature, you should switch off the choke function again. This is only needed for starting.
The last step is often to turn on the water supply via the water tap. However, this can depend on the machine, for example, with some machines the water supply must first be ensured before the pump runs. This is because they can be permanently damaged if they run dry.
With some models, a so-called primer / pump ball must be activated before starting. This sucks petrol into the carburettor with the help of negative pressure so that a richer fuel mixture is produced, which makes the starting process much easier. In principle, this function has the same function as the choke function.
Some premium models can be started like a car at the push of a button. These then have what is known as an automatic start.
However, this is expensive and is very rarely installed, as the cost-benefit factor is not given for most users.
As mentioned above, the starting process differs from device to device. With some, the choke is automatically switched off when the operating temperature is reached, and some manage without a primer for the starting process.
Still others can be started simply by pressing a button. For this reason, you should read the operating instructions thoroughly, as they explain the starting procedure and the steps to be taken in detail.
Checklist for starting
- Connect & turn on water supply
- Activate fuel supply
- Operate choke / primer
- Start the engine by pulling the cord.
- Reset the choke
Please read the operating instructions beforehand, the steps listed here may differ.
Pressure regulation of a petrol pressure washer
If a petrol pressure washer has a pressure regulator, this is implemented with the help of a pressure reducer. You can set the desired pressure with a small adjusting screw or knob. Of course, this is not as convenient as with a 230-volt Kärcher high-pressure cleaner, where you can set the pressure on the high-pressure lance.
However, petrol high-pressure cleaners often only have a pressure regulator from 700£ upwards. Cheaper models rely on so-called clip-on nozzles with variable diameters. The principle behind these is quickly explained: with a small diameter, the pressure is increased because the same amount of water acts on a smaller area, and with a larger diameter, the pressure is reduced.
This can be particularly disastrous when working with filigree surfaces. This is because you have no exact way of setting the pressure. You have to coarsely pre-select the pressure by choosing the nozzle and then “fine-tune” the pressure by adjusting the distance to the object. It can quickly happen that too much pressure is applied to the surface and it is damaged.
How a pressure reducer works?
A pressure reducer works as follows: There is an adjustable spring in the pressure reducer which presses down a valve. This valve is raised by the pressure upstream of the pressure reducer and pressed down by the pressure downstream of the pressure reducer.
By being able to adjust the spring pressure, the pressure after the pressure reducer can now be adjusted. When the set pressure is reached after the pressure reducer, the additional force of the spring closes the valve and no further pressure can be built up.
Why do petrol pressure washers use a pressure reducer?
A pressure reducer is used because it is hardly possible to regulate the pressure otherwise. It could be regulated by lowering and increasing the pump speed, but this is linked to the speed of the engine.
To be able to control the speed of the engine, either an expensive gearbox or a clever control unit would have to be installed. Since these two methods have only a slight advantage over a pressure reducer and they cost considerably more, these two alternatives are not installed.
Advantages and disadvantages of petrol pressure washers
FAQ
How much horsepower does the pressure washer need?
The PS figure is actually completely irrelevant for assessing performance. The important key figures are the maximum working pressure and the delivery rate. However, if you want at least as much power as a 230-volt high-pressure cleaner, you should opt for a 5-hp model.
How does a petrol pressure washer work?
The basic mode of operation is that a combustion engine drives a high-pressure pump. The high-pressure pump is no different from the “normal” electric models. The petrol engine is also often just a slight modification of a lawn mower engine. An internal combustion engine develops its power through the controlled explosion of petrol.
What distinguishes expensive petrol pressure washers from cheap models?
The differences from 500£ to 1000£ lie in the quality of workmanship and the performance data. From 1000£ onwards, additional features such as pressure regulation are added. Furthermore, features such as a detergent tank, a fully automatic starter and brass cylinder heads increase the purchase cost.
Who needs a petrol pressure washer
This question is quickly answered, all those who need independence from the mains and or require a very high litre output & pressures. The high performance is unmatched by 230 volt models. The only alternatives are inflexible high-voltage devices.
Richard Taylor
Richard Taylor is a passionate gardener and horticulturist who has been growing and caring for plants for over a decade. He has a deep knowledge of the latest tools and products for gardening, and he provides informative and engaging evaluations of the latest products on the market. If you're looking for the best tools and products to help you care for your garden, Richard is your go-to source for expert recommendations.
