Gas pressure washers are powerful, reliable and built to handle both residential and commercial use. We’ll show you what to look for when buying, including recommended products based on our research of 300+ models.
- 3,200 PSI and 2.5 GPM
- Honda GC190 engine (6HP)
- OEM Solutions axial cam pump
- 25 ft. hose, 16″ wand and 5 nozzles
- Detergent injection via siphon
- Warranty varies by part (1-5 years)
- 2,900 PSI and 2.3 GPM
- Ryobi OHV engine (5HP)
- Axial cam pump
- 35 ft. hose, 20″ wand and 5-in-1 nozzle
- Detergent injection via siphon
- 3-year warranty
The best gas pressure washer: Simpson MSH3125-S
We believe the Simpson MSH3125-S is the best gas pressure washer for homeowners and any general, non-commercial use. It has high quality parts and accessories and ideal power for almost any job, with a price reasonable for almost any budget. It’s the #1 highest-rated pressure washer on the market, earning a 92% buyer recommendation rate after combining thousands of reviews from six top retailers.
The MSH3125-S has a 90% recommendation rate (based on 5,000+ verified reviews from six sources). It’s the best-selling gas pressure washer at Amazon and Pressure Washers Direct, and it’s top three at Home Depot and Lowe’s.
The Simpson MSH3125-S sits on the border between medium and heavy-duty power, which allows it to handle the widest variety of jobs. With 3,200 PSI and 2.5 GPM, the company lists almost every common job as a suggested use, including vehicles, patios, fences, siding and driveways. They don’t specifically mention substances, but it’s safe to say materials like moss, oil and sap can be easily washed away.
The MSH3125-S is powered by a Honda GC190 engine and OEM Technologies axial cam pump. This is the best engine and pump combination you’ll find on a residential gas pressure washer. The Honda GC190 engine starts easily, runs smoothly and can be maintained by anyone (oil changes take minutes). The OEM Tech. axial cam pump is double-sealed, maintenance-free and features stainless steel pistons for better efficiency, along with a steel unloader to manage internal pressure.
Although it’s part of their residential series, Simpson built the MSH3125-S to the same standards as their commercial models. The frame is 16-gauge steel with 10” pneumatic wheels, designed like a trolley for easy lifting and rolling. The engine is mounted on a 1/4″ steel base plate which reduces vibration, and accessories are securely held in an integrated holster at the top of the frame.
There are some recurring reviews about the MSH3125-S having engine trouble, sometimes out of the box but mostly after being stored. The Honda GC190 engine has a pretty good track record, so we think this may have more to do with improper maintenance. If you don’t have experience with gas power equipment, read up on proper methods before buying.
See how the MSH3125-S compares to other categories in our guide to the best pressure washers.
The best budget gas pressure washer: Ryobi RY802900
We believe the Ryobi RY802900 is the best budget gas pressure washer. It’s about $50 more expensive than the cheapest gas models (which cost around $250), but for the small price bump, you’re getting name brand equipment with better quality. Although it can only be purchased at Home Depot, it’s the most reputable product in the lower price range.
The RY802900 has a 95% recommendation rate (based on 3,000+ verified reviews from three sources). It’s the second best-selling gas pressure washer at Home Depot.
At 2,900 PSI and 2.3 GPM, the Ryobi RY802900’s cleaning power is slightly below average compared to other gas models in the residential category. The difference isn’t very noticeable for most jobs around the house, like cars, decks or other exterior surfaces. However, it could take some extra time to wash away thicker, heavier substances.
The main compromise you’ll make buying a cheaper gas pressure washer is a less desirable engine and pump. The RY802900 has a Ryobi-branded engine and axial cam pump, and while most customers are happy with their performance, the real manufacturers behind these components are a mystery. This isn’t always bad, but generally it’s more reassuring to have a recognizable engine and pump, plus it’s easier to find replacement parts if you need them down the road.
Convenience is where the RY802900 excels. It’s built like a hand truck with an aluminum frame and large 12” wheels, making it easy to maneuver. Ryobi includes a 35 ft. non-marring hose, which is 10 ft. longer than any other model in this price range, plus an adjustable nozzle with five stream patterns. Detergent can be injected via siphon, with two soap settings included on the nozzle.
Besides the engine and pump, one other issue with budget products is the use of plastic parts, and the RY802900 has a few. Some parts on the engine, wheels and hose have been found to loosen or crack over time. We can’t blame Ryobi for keeping their cost down by using plastic instead of metal in certain areas, but keep this in mind if you demand serious durability.
The best commercial gas pressure washer: Simpson PS4240
We believe the Simpson PS4240 is the best commercial gas pressure washer. It’s designed for pressure washing businesses and other professionals who demand extreme power and reliability, using the best components available from the most trusted brands. It’s the #1 best-selling and highest-rated product in the heavy-duty category, tested in-house before delivery to guarantee performance.
The PS4240 has a 91% recommendation rate (based on 500+ verified reviews from six sources). It’s one of the top five commercial pressure washers at Home Depot, Lowe’s and a few other retailers.
Businesses encounter many types of jobs, both small and large. The Simpson PS4240 is prepared for both. At maximum cleaning power, it has 4,200 PSI and 4.0 GPM, capable of stripping paint and cleaning any debris in record time. When this level of pressure isn’t necessary, you can easily adjust it at the pump, which is helpful to avoid damaging softer surfaces like wood and brick.
The PS4240 can run every hour of the day, every day of the week thanks to a Honda GX390 engine and AAA triplex plunger pump. The GX390 is Honda’s most popular commercial series engine, with a forged steel crankshaft, 1.6-gallon fuel tank and low oil shutdown. AAA’s triplex pump is equally desirable, being the company’s top-of-the-line product with an adjustable unloader valve, thermal relief protection and a sight glass for viewing oil level instead of a dipstick.
Weighing 138 lbs, the PS4240 does require some muscle to move, but the trolley-style steel frame and 13” pneumatic wheels provide a good center of gravity and decent leverage. You shouldn’t have to move it much though, since Simpson includes a long 50 ft. steel-braided hose to expand your operating area. Even with its length, the hose, nozzles, spray gun and wand can all be securely stored onboard.
The PS4240 has an exceptional record, which is hard to achieve. Only a small percentage of customers had bad stories to tell, including a few pump failures and damage upon delivery. In total, these reviews don’t account for much and aren’t recurring, so we don’t consider them red flags. With any product, defects are possible, but that’s why there are return periods and warranties.
How to choose a gas pressure washer
Learn what to look for when buying a gas pressure washer. We’ll show you ideal ranges for PSI and GPM, as well as advantages and disadvantages over electric-powered models. We’ll also list important parts and accessories, including a discussion on types and brands of engines and pumps.
PSI, GPM and CU/CP
Pressure is measured in pounds per square inch (PSI) and volume is measured in gallons per minute (GPM). Together, these two figures determine a pressure washer’s overall cleaning power, which is sometimes displayed as CU (cleaning units) or CP (cleaning power).
Gas pressure washers are available from around 2,000 PSI and 2.0 GPM up to and over 5,000 PSI and 5.0 GPM. Generally, you get the more versatility and the best value for your dollar in the medium and heavy-duty range, around 2,500-3,500 PSI and 2.5-3.5 GPM.
Gas vs. electric
Gas pressure washers are often recommended over electric models because they’re more powerful. Extra power is certainly helpful, but electric pressure washers have several good selling points too. If you’re not quite sold on gas power, compare both types below to see which is better for you.
- Gas models clean deeper and quicker because engines produce higher PSI and GPM.
- Gas models can be used more frequently and for longer hours because engines are more durable than motors.
- Gas models can be used anywhere because they don’t require an electrical outlet.
- Gas models can be harder to use because they require routine maintenance, plus there are more steps on startup.
- Gas models are harder to move because they’re bulkier and heavier weight.
- Gas models can’t be used indoors (if restrictions apply) because they’re louder and produce exhaust fumes.
- Gas models are more expensive, making them less accessible for lower budgets.
Features to look for
Parts and accessories vary by price, but availability also depends on residential or commercial purpose. Some features are good for everyone, while others are only recommended for certain use cases. Buy the best gas pressure washer based on the following features.
- Reliable, name brand engine. There are many variants of engines. For simplification, we’ve created three categories: brandless, rebranded and name brand. Brandless engines have no specified brand or manufacturer. Rebranded engines have the name of the pressure washer brand, but they’re not the engine manufacturer. Name brand engines have the name of the engine manufacturer. Brandless and rebranded engines are less expensive, but usually less reliable. Name brand engines are more expensive, but usually more reliable, plus maintenance tends to be easier and replacement parts are easier to find. Notable brands include Honda (GC and GX series), Kohler (RH and CH series) and Briggs & Stratton. Brand name aside, also look at engine features that affect usability, like power output, fuel tank size and oil reservoir location.
- Reliable, name brand pump. There are three types of pumps, but only two are used on gas pressure washers: axial and triplex. Axial pumps are less expensive and designed for general use. Triplex pumps are more expensive and designed for daily use. Similar to engines, branding is important for estimating reliability. Follow the same principles as engines when choosing pump brands (name brands are best). Notable brands include AAA, OEM, CAT and Annovi Reverberi.
- Durable, portable frame. Gas pressure washers are heavy, weighing anywhere between 50-200 lbs. As weight increases, it’s important that the frame supports the load and remains reasonably simple to transport. Steel is stronger and provides better vibration dampening than aluminum, and wheelbarrow (or trolley) frames are easier to move than hand truck (or dolly) frames.
- Pneumatic wheels. No matter how big they are, plastic or polyurethane wheels will never be as smooth or durable as pneumatic wheels, especially on uneven terrain like gravel, grass or dirt.
- Braided hose. High pressure hoses are fairly durable by nature, but braiding makes them highly resistant to punctures, kinks and other damages. Steel braided hoses are most durable, but any form of braiding is better than none.
- Siphon detergent injection. Detergent can be injected via siphon tube or using an onboard detergent tank. Siphon tubes are easier to use because you can pull detergent straight out of the bottle, which means less setup and cleanup.
- Electric starter. If an injury makes it hard to use a recoil starter or you simply don’t want to deal with one, electric start gas pressure washers are available. There are a few models under $500, but most are over $1,000.
- Hot water. If time is a serious priority or you’re frequently dealing with thick, heavy substances, consider investing in a hot water gas pressure washer. Heating systems are only found on commercial models over $2,000, but their cleaning power is unmatched.
Frequently asked questions about gas pressure washers
Some of the most common questions about buying a gas pressure washer are answered here. For questions about specific products, we’re happy to offer advice, but depending on the question, you may receive better information contacting the manufacturer.
What kind of gas does a pressure washer use?
This depends on the engine brand and model. Most gas engines used on pressure washers, including Honda’s GC and GX series and Kohler’s RH and CH series, recommend unleaded gasoline with an octane rating of 87 or higher. Ethanol-based fuels, like E85, are usually not approved unless explicitly stated. Verify acceptable fuel types with the engine manufacturer before adding fuel.
What kind of oil does a gas pressure washer use?
This depends on the engine brand and model. Most gas engines used on pressure washers, including Honda’s GC and GX series and Kohler’s RH and CH series, recommend SAE 10W-30 oil for general, all-temperature use. Synthetic oil is usually not required, but recommended for better performance. Verify acceptable oil types with the engine manufacturer before adding oil.
How to start a gas pressure washer?
Starting a pressure washer requires a few steps, but it doesn’t take more than a minute. Assuming there are appropriate fuel and oil levels, you open the fuel valve, choke and throttle, then switch the engine to ON. While holding the trigger on the spray gun, pull the starter. Good engines start on the first pull, but some may take a few tries. Once the engine starts, give it some time to warm up, then close the choke and begin washing.
How long can you run a gas pressure washer?
This depends on the fuel tank size and the fuel efficiency of the engine. Generally, gas pressure washers will run for about 4 hours per gallon with regular use. The pump type may also be a consideration. It’s not common, but some cheaper axial pumps can overheat after too many hours of continuous use.