Wash gear
Foam cannons compared: which one fits your washer
Fifteen pressure washer foam cannons from eight makers: the fitting, the orifice, the PSI and GPM each maker allows, the bottle, and the soap mix. Check them against your own washer.
Which foam cannon fits an electric pressure washer?
Check the flow first. The nine corded electric washers in our washer comparison are rated 1.2 to 2.1 GPM. Some cannon makers state a minimum flow above 1.2 GPM, the lowest of these.
- Flow minimums: two makers set a minimum flow above 1.2 GPM for their cannons: Adam's Polishes 1.3 GPM and Chemical Guys 1.4 GPM. Four of the nine washers flow less than even the lowest of these: Kärcher K1800PS (1.2 GPM), Sun Joe SPX3000 (1.24 GPM), Ryobi RY142300 (1.2 GPM), and Greenworks 2000 PSI 1.2 GPM (GPW2003) (1.2 GPM).
- Within every stated limit: MTM Hydro PF22.2, Griot's Garage Brilliant Finish Foam Cannon, AR Blue Clean Pro F6 Foam Cannon Kit, AR Blue Clean FL803 Premium Foam Cannon Kit, AR Blue Clean AR5940K Universal Foam Cannon Kit, and Greenworks Premium Foam Cannon (PAQ701) are within every PSI, GPM, and CU limit their makers state for all nine washers. The makers of MTM Hydro PF22.2, AR Blue Clean Pro F6 Foam Cannon Kit, AR Blue Clean FL803 Premium Foam Cannon Kit, AR Blue Clean AR5940K Universal Foam Cannon Kit, and Greenworks Premium Foam Cannon (PAQ701) state only maximums, so nothing rules out a weak washer for those.
- The orifice: only MJJC, Griot's Garage, and AR Blue Clean tie the orifice to the washer, and their rules use different inputs. For the Kärcher K1800PS (1,800 PSI, 1.2 GPM, 2,160 CU): MJJC's chart names 1.25 mm (installed) for 1,800 PSI. 2,160 CU is not above 4,000 CU, so keep the 1.1 jet Griot's installs for most electric washers.
Check your washer
Pick a washer from our comparison or type the PSI and GPM from your washer's label or manual. Each cannon is checked only against the limits its maker states, and the orifice comes only from a maker's own rule.
Pick a washer or enter its PSI and GPM.
Foam cannons compared
| Foam cannon | Fitting | Orifice | Washer range | Bottle | Materials | Soap mix | Maker price | Shop |
|---|---|---|---|---|---|---|---|---|
| MJJC Foam Cannon Pro V3.0product page, compare page | 1/4" quick connect (an M22 x 1.5 version is sold) | 1.25 mm installed; 1.1 mm and 1.35 mm in the box | “1300-4,400psi” (compare page); “minimum of 50 BAR/725 PSI” (product page); cold water onlyThe two MJJC pages give different minimums. The check uses the higher one, 1300 psi. | “1200ml+” | Metal parts: stainless steel and brass | “100ml shampoo with 900ml water” (MJJC FAQ) | $109.00 | Search Amazon for MJJC Foam Cannon Pro V3.0 |
| MJJC Foam Cannon S V3.0product page, compare page | 1/4" quick connect (an M22 x 1.5 version is sold) | 1.25 mm installed; 1.1 mm in the box | “1300-3600psi” (compare page); “minimum of 50 BAR/725 PSI” (product page); cold water onlyThe two MJJC pages give different minimums. The check uses the higher one, 1300 psi. | “1000ml” | Metal parts: solid brass | “100ml shampoo with 900ml water” (MJJC FAQ) | $89.00 | Search Amazon for MJJC Foam Cannon S V3.0 |
| MTM Hydro PF22.2product page, brochure | Choice of nine inlets, including M22 male, M22 female, G 1/4 and bayonet | 1.25 mm in the brochure (other sizes not stated) | “Rated Pressure: 2900 psi”; “Rated Flow: 3 U.S. gal/min”MTM gives rated figures (and “Permissible Pressure: 3200 psi”); the check treats the rated ones as maximums. MTM sells by quote and lists no price. | “1 lt” (0.264 U.S. gal.) | Not stated | Not stated | Not listed | Search Amazon for MTM Hydro PF22.2 |
| Chemical Guys TORQ Max Foam 8product page | 1/4" quick connect | Not stated | “500-3,500 PSI”; “Minimum 1.4 GPM; 2.0 GPM recommended; Never Exceed 5.3 GPM”The maker also says never exceed 4,200 PSI. The check uses 3,500. | Takes “32 oz. bottles” (capacity not stated) | Brass parts and plastic | “Add 1-3 ounces of car wash soap” to the tank of warm water | $99.99 | Search Amazon for Chemical Guys TORQ Max Foam 8 |
| Chemical Guys Big Mouth Max Releaseproduct page | Quick-release (size not stated) | Not stated | “800-3,500 PSI”; “Minimum 1.4 GPM; 2.0 GPM recommended; Never Exceed 5.3 GPM”The maker also says never exceed 4,200 PSI. The check uses 3,500. | “34 oz.”, wide opening | Not stated | “Add 1-3 ounces of car wash soap” to the canister of warm water | $99.99 | Search Amazon for Chemical Guys Big Mouth Max Release |
| Chemical Guys TORQ Professional Snow Foam Cannonproduct page | 1/4" quick connect | Not stated | “500-3,500 PSI”; “Minimum 1.4 GPM; 2.0 GPM recommended; Never Exceed 5.3 GPM”The maker also says never exceed 4,200 PSI. The check uses 3,500. | Not stated | Brass parts and plastic | Not stated | $89.99 | Search Amazon for Chemical Guys TORQ Professional Snow Foam Cannon |
| Adam's Standard Foam Cannonproduct page, explainer | 1/4" quick connect | Not stated | “870-3190 PSI”; “1.3-5.3 GPM” | “33.81 Ounce” | Not stated | “Use 2-5 Ounces Of Your Preferred Shampoo” | $59.99 | Search Amazon for Adam's Standard Foam Cannon |
| Adam's Premium Foam Cannonproduct page, explainer | 1/4" quick connect | 1.25 mm | “870-3190 PSI”; “1.3 – 5.3 GPM” | “35oz”, wide mouth | Stainless steel head | Not stated | $64.99 | Search Amazon for Adam's Premium Foam Cannon |
| Griot's Garage THE BOSS Foam Cannonproduct page, manual, troubleshooting guide | 1/4" quick coupler plug shown fitted in the manual; M22 adapter sold separately | 1.25 jet installed; 1.1 jet in the box | “minimum of 1,980 CU (Cleaning Units = GPM x PSI)”; “Never operate … with more than 3,600 psi”The manual also says not to exceed 5000 psi. The table uses its lower limit, 3,600 psi. | “33.8 oz” | Stainless steel manifold and barrel | “2-3 ounces of concentrate” for most soaps; BOSS soaps “20:1” | $99.99 | Search Amazon for Griot's Garage THE BOSS Foam Cannon |
| Griot's Garage Brilliant Finish Foam Cannonproduct page, manual | 1/4" quick connect; M22 adapter sold separately | 1.1 jet installed; 1.25 jet in the box | “1,100-5,000” PSI; “1.2-5.3” GPM; “minimum of 1,540 CU” | “33.8 oz” | Electroplated aluminum manifold and barrel | Pre-mixed: 3.75 oz Brilliant Finish Car Wash to 30 oz water (“8:1”) | $64.99 | Search Amazon for Griot's Garage Brilliant Finish Foam Cannon |
| AR Blue Clean Pro F6 Foam Cannon Kitproduct page | 1/4" quick connect installed; M22 fitting in the box | 1.3, 1.5 and 1.8 mm in the box (installed size not stated) | “Max Pressure (PSI) 4,000”; “Max Rated Flow (GPM) 4” | “34 oz.” | 316 stainless steel | “a 20:1 detergent dilution ratio” | $89.00 | Search Amazon for AR Blue Clean Pro F6 Foam Cannon Kit |
| AR Blue Clean FL803 Premium Foam Cannon Kitproduct page | 1/4" quick connect plug | 1.25 mm | “2,900 Max PSI and 4.8 Max GPM”The same page also says up to 4,000 PSI and a 34-ounce bottle. The table uses 2,900 PSI and 32 oz from its spec list. | “32” oz | Brass | Not stated | $78.95 | Search Amazon for AR Blue Clean FL803 Premium Foam Cannon Kit |
| AR Blue Clean AR5940K Universal Foam Cannon Kitproduct page | Kit has bayonet, 1/4" quick connect plug and M22 x 1.5 adapters | 1.25 mm | “up to 4,000 PSI and 2.4 GPM”; “Works with most electric pressure washers”The spec list says the container holds 35 oz. | “34 oz.” | Not stated | Not stated | $59.95 | Search Amazon for AR Blue Clean AR5940K Universal Foam Cannon Kit |
| Greenworks Premium Foam Cannon (PAQ701)product page | 1/4" quick connect | Not stated | “Max PSI 3100 PSI”; “Max Water Flow 3.0 GPM”The same page also says up to 3700 PSI. The table uses 3100 PSI from its spec list. | “1 Liter”, wide mouth | Plastic (the spec list does not say which part) | Not stated | $39.99 | Search Amazon for Greenworks Premium Foam Cannon (PAQ701) |
| Ryobi Premium Foamer (RY31PF05)product page | 1/4" quick connect | Not stated | Not stated | “34 oz” | Not stated | Not stated | $44.97 | Search Amazon for Ryobi Premium Foamer (RY31PF05) |
"Not stated" means the maker's pages we read do not say it. Prices are the prices on each maker's own store on October 26, 2026; sellers on Amazon set their own.
How to use a foam cannon
- Fill the bottle with warm water first, then add the soap. Adam's says to fill it about 4/5 full with warm (not hot) water before the soap.
- Add the amount your soap and cannon makers give. Our car shampoo comparison lists each shampoo maker's foam cannon amount where one is given.
- Attach the bottle, then connect the cannon to the wand with its 1/4 inch quick connect or M22 fitting.
- Set the top knob for more or less soap and turn the nozzle from a narrow stream to a wide fan. Griot's says turning its Brilliant Finish dial all the way clockwise typically gives the most foam.
- After the wash, run clean water through the cannon. Griot's guarantee does not cover a foaming mesh clogged because the unit was not flushed after use.
If the foam is thin on a smaller washer, check the orifice rule for your cannon in the check above. To mix any other cleaner from its label ratio, use the dilution calculator.
Questions
Do foam cannons work with electric pressure washers?
Many do, but check the flow. The nine corded electric washers in our comparison are rated 1.2 to 2.1 GPM. Two cannon makers set a minimum flow above 1.2 GPM (Adam's Polishes 1.3 GPM and Chemical Guys 1.4 GPM), and four of those washers flow less than even the lowest. MTM Hydro PF22.2, Griot's Garage Brilliant Finish Foam Cannon, AR Blue Clean Pro F6 Foam Cannon Kit, AR Blue Clean FL803 Premium Foam Cannon Kit, AR Blue Clean AR5940K Universal Foam Cannon Kit, and Greenworks Premium Foam Cannon (PAQ701) are within every limit their makers state for all nine.
What orifice size should I use in a foam cannon?
Use your cannon maker's rule. MJJC sets the orifice by pressure: 1.1 mm for 1,305 to 1,595 PSI and 1.25 mm for 1,595 to 2,175 PSI. Griot's Garage sets it by cleaning units (PSI × GPM): the 1.1 jet below 4,000 CU and the 1.25 jet above. The two rules can disagree. For the Kärcher K1800PS (1,800 PSI, 1.2 GPM, 2,160 CU), MJJC's chart names 1.25 mm and Griot's names the 1.1 jet. Most other makers publish no orifice rule.
How much soap goes in a foam cannon?
Follow the soap and cannon makers. Chemical Guys says 1 to 3 ounces of car wash soap in the tank of warm water. Adam's says 2 to 5 ounces for its Standard cannon. MJJC says 100 mL of shampoo with 900 mL of water. For its Brilliant Finish cannon, Griot's gives a pre-mix chart by soap, such as 3.75 oz of its Brilliant Finish Car Wash to 30 oz of water.
What fitting does a foam cannon need?
Most cannons here connect with a 1/4 inch quick connect plug. Some washers use an M22 x 1.5 thread instead. MJJC sells its cannons in an M22 x 1.5 thread version too, and its M22 parts come with a 14 mm or a 15 mm inner hole. Check the thread on your gun or wand before you order. MJJC also sells versions for Kärcher K-series guns, and Kärcher's own FJ 6 foam nozzle is made for K1 to K5 washers.
Sources and limits
Each cannon's pages are linked in the table, read October 26, 2026. MJJC's orifice chart is on its Pro V3.0 page; its FAQ gives different limits: the 1.1 mm orifice up to 1,700 PSI, and 1.35 mm only above 180 bar. The check notes both. Where a maker gives two figures for the same thing, the row note says which one the table uses. Nobody tested these cannons for this page. Kärcher's FJ 6 is left out because it is a detergent-bottle foam nozzle for Kärcher K1 to K5 washers, not an air-intake foam cannon with a swappable orifice. We also left out cannons the maker's store showed as unavailable (Sun Joe SPX-FC34-MAX, Autofiber) and models with no washer figures or an older version of a listed cannon (Ryobi RY31F06, MJJC Pro V2.0).
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