Mobile Detailing Water Tank Size Guide – Pick The Right Tank

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water tank for mobile car detailing

When buying a water tank for your mobile detailing business, you shouldn’t buy either too big or too small a tank. In this guide, I’ll show you what’s the ideal size of water tanks for most mobile detailers and what you should pay attention to when purchasing one.

Key Takeaways:

  • The best water tank size for mobile detailers is anywhere between 50 and 100 gallons.
  • You should always make sure that you have enough space for a water tank.
  • There are different types (shapes) of water tanks, so you can fit them in your mobile detailing van or truck.

Best Overall Water Tank Size – 50 to 100 Gallons

As I already said, the best overall water tank size for mobile auto detailing is anywhere between 50 and 100 gallons. Whether you choose a 60-gallon tank or a 100-gallon one, you’ll be able to do car washes.

It’s a slightly more extensive range, but I had to put it like that since not every detailer has the same detailing setup, the exact size of a vehicle, etc. A 100-gallon tank will barely fit into a VW Caddy and leave enough space for the rest of the detailing gear. 

On the other side, fitting a 100-gallon water tank in a Ford Transit van is a piece of cake, with plenty of room left for other stuff such as a pressure washer, power generator, polishers, wash buckets, etc. 

For instance, on average, a 50-gallon water tank should be enough to wash 3-6 vehicles, which is more than enough, in my opinion. Some people even managed to wash 10 cars out of that tank, but I don’t think they were too “detailed” when washing cars. 

Pros and Cons of Larger Water Tanks


  • You’ll always have plenty of water
  • No need to fill it so often
  • You can be more detailed since there’s no need to save every gallon of water


  • It is not convenient for smaller detailing setups.
  • It can be heavy for your car

Pros and Cons of Smaller Water Tanks


  • Easier to fit inside any vehicle
  • It’s not a problem to take it out if needed (to wash it, etc.)
  • Much cheaper (there are more competitors, which means better prices)


  • It is not the best if you wash more than 6 cars a day.
  • You may have to fill it through the day

How To Choose The Right Size of Water Tank

water tanks of various sizes

I gave you some information that you should know before choosing the water tank that’ll fit your needs and be beneficial to your auto detailing business. Now, I want to show you a quick guide for choosing the right water tank for you. 

Before buying a water tank for your mobile detailing business, check the following factors. 

1. How Many Cars Do You Wash Per Day

The number of car washes is the most crucial factor you should consider before buying a water tank for a mobile detailing business.

If you’re only washing 2-3 vehicles a day, which is mostly the case because of a complete interior and exterior cleaning, a 50-gallon water tank should be more than enough for you. 

On the other side, if you do 5-10 car washes a day, you should consider buying a larger tank, something around 100 gallons. Those will mostly be people doing only exterior washes and have time to do up to 10 cars a day.  

I advise you to choose the water tank that has enough capacity to clean one more vehicle than you’re usually doing. That way, you’ll ensure enough water supply for all kinds of situations. 

2. How Often You Need a Water Tank

Even though you are a mobile detailer, it doesn’t mean that you’re using a water tank the whole time. There will still be many situations when you connect to the client’s water source. 

If you only rarely need a water tank, don’t spend an extra few hundred bucks to buy a large tank that you never need. Always choose something that has a good ROI (return on investment). That’s the only way to keep your business up and running.

Even though I’m sharing this advice with you, if you think that a 25-gallon is enough for you, get it. It’s not wrong. In the end, you’re the one that will use it, and you know exactly how much water do you need each day. 

3. The Way You Wash Vehicles

There are thousands of detailers out there, and almost nobody uses the exact same method and techniques for washing cars and trucks. In order to choose the right size water tank, you have to calculate everything you’re doing when washing vehicles. 

If you’re like me and love to do everything the best possible way, you’ll always thoroughly wash vehicles with plenty of cleaning steps. For instance: Pre-rinse, foam, rinse, contact wash with shampoo, final rinse. Those are the steps I usually take, and they guarantee spotless cars. Then, if you use a 3-bucket method, which is the best out there, you’ll also spend more water. 

However, if you don’t usually do so many steps when washing vehicles, you won’t spend as much water as I do. That way, with the same size water tank, you’ll be able to detail more cars than me. 

If you’re doing so many steps, go with a larger tank. A 100-gallon tank is more than enough for anyone, and it’s a great choice if you can fit it inside your car or truck. 

Furthermore, you should know the GPM flow of your pressure washer. Every pressure washer has that in manuals, or you can find it on Google. That way, you’ll know how many minutes you can run your pressure washer without worrying about the water supply. 

4. What Vehicle Do You Use?

Last but not least is the type (size) of the vehicle you’re using for your mobile detailing business. It’s easy to buy the most giant tank out there, but fitting it into the car is more complex. 

If you have a mid-sized car, it’s already full of auto detailing equipment, and fitting a 100-gallon tank inside is almost a mission impossible. For mid-sized vehicles, I would always choose a ca. 50-gallon water tank. 

On the other hand, if your mobile detailing vehicle is some van, truck, or big SUV, you’ll have more space. With that said, you’ll be able to fit a larger water tank inside. 

The best thing you can do is measure everything and see how much space you have to fit the water tank inside. Don’t forget that there are also different shapes of water tanks to fit in a specific vehicle. 

You can choose both vertical and horizontal water tanks, and I don’t think you’ll have problems choosing one. The market out there is pretty broad, and you should be able to find something that fits your detailing setup the best. 

I have found two great water tanks that you can get for your mobile detailing setup. Make sure to check them out. It wasn’t hard to find them, but some rip-offs are “specific for auto detailing,” don’t fall for those marketing tricks. 

Blue 55-Gallon Water Tank by WaterPrepared

WaterPrepared 55 Gallon Unique Space Saving Stackable Design Utility Water Tank with Large Cap for...

I know the Blue 55-Gallon Water Tank is not the prettiest tank out there, but it’s great for mobile detailing setups. It’s a vertically designed tank to fit inside your vehicle effortlessly.

You have a large tank cap on the top, which is fantastic for quickly filling the tank with water. At the bottom, there’s a spigot that fits garden hoses so that you can connect it to the water pump or pressure washer too.

The best thing about this tank is that it’s made out of high-quality UV-resistant plastic that keeps the water inside the tank fresh. So, you can even drink that water if you don’t have anything else to drink. 

WaterPrepared is a USA company that makes these tanks in Utah. So, you don’t have to worry about cheap and low-quality Chinese manufacturers. The only disadvantage is that you’ll have to find a way to fix it inside your car, but it’s not a problem with some tie-down straps. 

Dimensions: 22″ x 28″ x 30″

If this tank has enough capacity for your needs and it also fits inside your vehicle, that’s a perfect choice. 

100-Gallon Water Tank by DetailKing

Water Tank 100 Gallon - 38.5" x 26.5" x 25" - Mobile Detailing Work - Holds Enough Volume for 10-15...

This 100-Gallon water tank by DetailKing is a specifically designed water tank for all mobile detailers. In their store on Amazon, you can choose between many different water tanks, depending on the size you need. 

The price tag is a bit higher, but it’s due to the high-quality materials used to build this fantastic water tank that can provide you with enough water to wash around 7-10 mid-sized vehicles. 

It’s UV-resistant, so you can use it outside too. The plastic won’t damage. To better fit inside your car, there are molded slots for tie-down straps. That way, the tank won’t wiggle when you’re driving the vehicle. 

Dimensions: 38.5L” x 26.5W” x 25H”

If you need a larger tank like this one, this could be a great choice. However, shipping costs tend to be high, so think about picking it up yourself. You’ll save a lot of money. 

How Many Gallons of Water Does It Take To Wash a Car?

Before I can continue with the topic, I should answer this question too. I believe that everyone wants to know the exact number of gallons needed to wash the vehicle properly. 

On average, detailers spend anywhere between 10-30 gallons to wash a mid-sized vehicle. However, it depends on the methods used for cleaning it.

As you can see, it’s hard to tell the exact number. Every detailer uses different techniques and methods to clean vehicles, which is why I told you it’s somewhere between 10-30 gallons per vehicle. And of course, for some large SUVs, you can spend a bit more.

For instance, someone who follows my full guide for a proper car wash will pre-rinse the car, snow foam it, wash it, and rinse it once more. That way, you’ll use more water, but it’s worth taking fantastic results into the count.

Furthermore, these numbers are the average when using high-pressure washers, usually having a GPM (Gallons per minute) between 1.2 and 1.8. So, if you use a 1.2GPM high-pressure for 10 minutes, you’ll spend 12 gallons – which is entirely reasonable. Of course, add 5-6 gallons of bucket water.

If you use a standard garden hose, you can easily spend 50+ gallons per vehicle since most garden hoses have a flow of around 10 GPM. 


Choosing the right size water tank for your mobile detailing business isn’t hard. You only need to know all the factors I mentioned above, and you’re ready to pick one that’ll fit your needs. 

As I already said, I was mentioning some averages. Still, everyone’s different, and you might need a larger or smaller water tank, depending on your specific needs and techniques used when washing vehicles. 

Again, in my opinion, any water tank between 50 and 100 gallons is perfect for every mobile detailing business.

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