Suds or Duds? The Best Foam Cannons for 2024, Tested

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Handwashing your car can be a time-intensive project. While there are few shortcuts to a great finish, one tool is capable of not only speeding up the process but also improving the end result: the foam cannon.

No, we're not talking about something capable of firing projectiles—we're talking about an attachment on the end of a pressure-washer wand that mixes the high-pressure water with soap to make a thick foam you can spray across your entire vehicle. There are plenty of foam cannons out there, but not all are worth their cost. Thankfully for you, we got our hands dirty and our cars clean to see which foam cannons are the best for washing your vehicle.

What to Consider When Buying a Foam Cannon

Do You Own a Pressure Washer?

All but one of the foam cannons on our list require a pressure washer to use. (If you don't own a pressure washer, then what you need is a foam gun that attaches to an ordinary garden hose.) A pressure washer ensures you'll get the best spray and suds possible for easier application and more robust coverage.

What's Your Budget?

Like any automotive tool, foam cannons range in price. Generally speaking, the more you pay, the more you get in terms of foam production, build quality, and usability. But there are diminishing returns, and sometimes you can be fooled by paying more for the brand than the product. Check out our test to see which brands live up to their names.

Frequency of Use

How often do you wash your car? Is it enough to justify the purchase of a foam cannon? If you only wash your vehicle a few times a year, it might not be worth the up charge over a bucket and sponge. But if you clean it weekly or even monthly, a foam cannon will save you time and likely deliver a deeper clean due to the extra suds you can get compared to hand washing.

How We Tested Foam Cannons

A foam cannon is a foam cannon, right? Not quite. For this test, we rounded up five of the most purchased and highly rated foam cannons online and put them through the wringer to see which one delivers the best results. We took extensive notes throughout the process and gathered both objective and subjective data to support our recommendations.

Here are the parameters we measured in our foam cannon test:

• Installation

• Foam production and behavior

• Features and materials used

• Spill test
  

• Min/max psi
  

• Additional notes on each product

After testing five foam cannons, we determined the best for various situations and uses. Here's what we found.

Big Mouth Max Release Foam Cannon

Chemical Guys Big Mouth Max Release Foam Cannon lives up to its name. Its adjustable mouth was the largest of all the units we tested and offered the widest spray pattern, with smooth foam that nicely held on to the surface of the vehicle. The metal fittings were sturdy, and while the bottle could probably be a bit wider for a more stable base when placed on the ground, the plastic itself was plenty thick enough. There was minimal leakage when the bottle was tilted upside down, and the 34-ounce bottle holds more than enough soap to get even the largest vehicles foamed up in a single session.

While all of this makes for the best overall unit we tested, it does come at a higher price than almost every other foam cannon on this list; whether that's worth the extra money or not is up to you.

Chemical Guys Foam Cannon Spray Pattern

Brilliant Finish Foam Cannon

The Griot's Garage Brilliant Finish Foam Cannon proved to be a reliable option that produced consistent foam that spread evenly and stayed put on the vehicle. Its adjustable mouth was easy to twist for the desired spray pattern, and while its soap concentration adjustment dial on the side was a bit small and tough to dial in, the weighted straw made up for this by ensuring no soap is left behind in the bottle, regardless of the angle you're spraying.

The male pressure-washer attachment didn't feel quite as robust as others on the list, but leakage was minimal when tipped upside down and everything else felt sturdy and well-constructed.

Griot's Garage Foam Cannon Spray Pattern

Premium Foam Cannon

Adam's Polishes Foam Cannon was one of the more sturdy units we tested. The 35-ounce bottle is stout, and its wide base made it easy to set on the ground while attached to the pressure-washer sprayer.

The aluminum male attachment point felt sturdy and the adjustable mouth on the end was smooth with a nice range of adjustment. Combine that with the easy soap adjustment dial on the top and you get a well-rounded unit that's easy to use and creates what we can only describe as a velvet-like spray that evenly coats the entire side of a vehicle.

Adam's Polish Foam Cannon Spray Pattern

Foam King Cannon Sprayer

Let's just get this out of the way—the Foam King Foam Cannon has no right to be as good as it is for the price. It provided an even spray with well-aerated foam that coated the side of our test vehicle, and its adjustable mouth and soap level dials both offered a range of versatility for getting just the right spray.

There was slight leakage when the bottle was tipped upside down but considerably less than some of the competition, including units more than double the price. As a whole, it's a great value that can get the job done without putting too much ache on the wallet.

Foam King Foam Cannon Spray Pattern

2-in-1 Foam Cannon Kit

Just like 2-in-1 shampoo, Armor All's 2-in-1 Foam Cannon leaves a lot to be desired in terms of performance. We used it with the same power washer we used to test all of these foam cannons, but the foam didn't aerate as well and the cannon dispensed it too heavily, leaving splotches and clumps of suds on our car.

For convenience though, Armor All gets a few points, as the included garden hose attachment means you don't need a pressure washer. Foam creation and distribution with the hose attachment was even less impressive due to the lower pressures, but it did produce a fair bit of foam—certainly more than your standard sponge or microfiber towel would produce.

All in all, the Armor All gets the job done but leaves much to be desired. What it lacks in performance, though, it makes up for in versatility.

Armor All Foam Cannon Spray Pattern

How We Tested Foam Cannons

How different can one foam cannon be from another? Turns out, a lot in some ways and not much in others. For this test, we wanted to see how some of the best-selling models stacked up against each other.

After assembling the foam cannons and loading them up with the same 8:1 soap-to-water ratio, we pulled up a well-loved but slightly neglected Acura TSX. To have a baseline, we gave the Acura a quick handwash and rinsed it off, being sure to leave a slight coating of water, per the recommendation of each foam cannon manufacturer.

From there, we dialed in each of the foam cannons to approximately the same soap output level using the integrated dials, and set each of the spray patterns to roughly midway between their adjustable ranges. With the help of our intern Alessandra, we sprayed the side of our test vehicle, from back to front, and let the foam settle for 60 seconds. We evaluated how the foam sprayed, distributed, bubbled, and adhered to the vehicle.

We thoroughly rinsed the car and repeated this process for each foam cannon we tested. We checked each unit for leaks by rotating it a full 360 degrees and leaving it upside down and on its sides to see how much soap mixture leaked from the bottle and both ends of the nozzle.

Don’t Own A Pressure Washer? You Need A Foam Gun

What’s the difference between a foam cannon and a foam gun? While the two terms are often used interchangeably, the general consensus is that a foam cannon connects to a pressure washer, while a foam gun is simply screwed onto your garden hose.

As we noted above, a foam gun won’t produce nearly as much foam as a cannon due to the lower water pressure involved. It will certainly get the job done, but the foam won’t spray as far and wide nor be as aerated as the foam cannon options. But sometimes you can only work with what you’ve got.

If you’re looking for something that can be used with a standard garden hose, here are a couple of the best-selling foam guns available. To be clear, neither of these was tested by the Gear Team, but they both come from trusted companies:

Chemical Guys Torq Foam Blaster 6

While not nearly as powerful as the company’s dedicated foam cannon above, the Torq Foam Blaster 6 works with your standard garden hose. The system features a dual action hose nozzle, a 32-ounce bottle, and an adjustable foam dial for getting just the right amount of soap.

Adam's Polishes Premium Foam Gun

This unit from Adam’s Polishes features a 35-ounce soap canister, a quick-connect nozzle with a standard garden hose connection. Adam’s Polishes offers four dilution ratios to dial in the amount of soap you’re using, but the company recommends you use it at the highest concentration for optimal coverage.

FAQs about Foam Cannons

What does a foam cannon do?

Foam cannons are devices you place on the end of a power washer that combines water and soap at a high pressure to then spray over a car. Using a foam cannon makes for more foam than standard handwashing will and enables you to coat your vehicle in much less time.

Are foam cannons suitable for all vehicles?

Foam cannons can be used on any vehicle, regardless of size. Larger vehicles might require a bit more time and effort, but there are no logistical restrictions in terms of usability.

What is the best ratio of soap to water?

The optimal ratio often depends on the specific foam cannon and soap you’re using. Generally, a common recommendation is a 1:10 soap-to-water ratio, but be sure to closely examine the instructions that come with your foam cannon and soap.

Do I waste soap while using a foam cannon?

While a foam cannon does consume soap during operation, it’s typically not a wasteful process. The cannon is designed to use soap efficiently. In fact, based on our testing, we feel confident saying you’ll likely use less soap than you would hand washing your vehicle.

Why Trust Us?

Hearst Autos combines the talent, resources, and expertise of three of the largest, most influential automotive publications in the world. The Gear Team has tested a wide variety of automotive products, parts, accessories, and gear, such as shop vacs, backup cameras, and EV chargers. We get our hands on each and every product we test. Most are purchased; some are supplied by manufacturers.

Hearst Autos doesn't need to game algorithms for traffic or promote lousy products to earn a buck. Instead, we're more concerned with our legacy, our reputation, and the trust that our readers have in Autoweek, Car and Driver, and Road & Track to deliver honest opinions and expert evaluations.

Visit our Tested & Trusted page to see the very best in automotive gear. Read more about our product testing and evaluation process here.

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