Water Tank Sizing For Mobile Auto Detailing

If you provide a mobile auto detailing service as part of a business, you will need a fair amount of equipment. 

One thing you will definitely need is a water tank because part of mobile detailing involves cleaning vehicles, and because the service is mobile, you will need to be able to do this independently of a water source. 

Water Tank Sizing For Mobile Auto Detailing

The problem is that it can be difficult to correctly estimate what size water tank you’ll need to provide a smooth and efficient mobile auto detailing service.

If you look up what water tank size you should use for mobile detailing, you’ll find that the answer can range from 50 gallons to 100 gallons.

However, in order to determine the specific size that you should be using, you’ll need to consider factors such as how many cars you typically wash in a day and the size and model of your own vehicle. 

By the end of this article, you will know what size water tank is right for your business.

How Many Gallons Of Water Will Wash A Car? 

The first place to start if you want to work out how large your water tank needs to be for mobile detailing is to find out how many gallons of water are required to wash a car. 

This can be a difficult estimate to make because, of course, it depends on the size of the vehicle in question. 

With that being said, an average-sized (mid-sized) vehicle usually requires about 20 gallons of water for a thorough clean.

This can vary from 10 to 30 gallons depending on the washing method you use. For example, if you follow the whole process of rinsing, foaming, washing, and doing a final rinse, you’ll use more water than if you skip the initial rinse. 

It’s also worth noting that the above estimate is only relevant if you’re using a high-pressure washer. 

High-pressure vehicle washers use between 1.2 and 1.8 gallons of water every minute. A quick, 10-minute wash with a high-pressure washer could, therefore, use as little as 12 gallons of water.

Add to that the 5 gallons of water you’ll need for your bucket, and that’s about 17 gallons. 

On the other hand, washing a car with a regular garden hose is far less economical when it comes to water usage.

This is because most garden hoses will use roughly 10 gallons of water each minute, meaning that if you spend 10 minutes washing a vehicle, you’ll be using 100 gallons of water.

You’ll probably have to spend longer washing with a regular hose as well, since the decreased pressure is less efficient at removing dirt and debris. 

The Optimal Water Tank Size 

As we mentioned previously, the average optimal size for a mobile detailing water tank is between 50 gallons and 100 gallons. 

You might be thinking that this is a pretty large estimated window, and you’d be right! However, the reason the range has to be this extensive is that not all mobile detailing services operate from the same type of setup. 

For example, let’s say you’re working out of a VW Caddy. This vehicle definitely wouldn’t be large enough for a 100-gallon water tank with all the other equipment you’ll need to carry.

In this situation, even though it might feel more practical to have 100 gallons of water at your disposal, you’d be forced to go with a smaller tank.

This wouldn’t necessarily be a problem since a 50-gallon tank can hold enough water to wash between 3 and 6 cars, depending on vehicle sizes. 

Conversely, if you’re using a van like a Ford Transit, you’ll have plenty of space for a 100-gallon tank, plus enough space for your generator, buckets, pressure washer, and polishing tools.

You could wash up to 12 vehicles with a 100-gallon tank, so if you have a large van at your disposal and lots of customers to attend to, this seems like the best option. 

Small Water Tanks: Benefits And Drawbacks

Bigger isn’t always better when it comes to mobile detailing water tanks. In fact, in some situations, less can be more. 

Smaller water tanks fit much more easily into vehicles of any size. If you opt for a smaller water tank, you don’t have to worry about whether you can fit your tank into your van or car alongside all your detailing gear. 

Water tanks that are on the smaller side also have the added benefit of being easier to handle and maneuver. If you need to wash your water tank, for example, this will be much less stressful if you have a smaller tank. 

Plus, small water tanks are less expensive because less material is used in their construction and there is more competition in the market for small tanks, leading to lower prices.

If you have a lot of customers, however, a small tank might not be ideal. A smaller tank (around 50 gallons) will only allow you to wash up to 6 vehicles before you need to refill it. 

Large Water Tanks: Advantages And Disadvantages

Large Water Tanks: Advantages And Disadvantages

With a larger water tank (closer to the 100-gallon mark), you won’t have to worry about running out of water throughout the day because this many gallons of water can wash up to 12 vehicles before you’ll need to fill it again. 

This also means that you can afford to be more meticulous with your detailing because you don’t have to try and conserve every last drop of water. 

Unfortunately, whether or not you can benefit from the advances of a larger water tank will depend on your detailing setup and the size of your vehicle. If you have a smaller vehicle, a 100-gallon tank may be too large or heavy.

How To Choose The Best Water Tank Size?

Earlier in this guide, we stated that choosing the ideal water tank size for your mobile auto detailing setup involves considering a number of factors related to the service you provide.

We’re going to go into further detail on all of these factors now. 

Number Of Cars Washed Per Day 

The size of the water tank you choose to incorporate into your detailing setup will dictate how many cars you can wash in a day.

Therefore, a good place to start when making your decision is to work out how many vehicles you typically wash each day. 

For example, if you wash between 2 and 3 cars on average every day, you shouldn’t have a problem using a 50-gallon water tank because tanks of this size have the capacity to wash up to 6 mid-sized cars.

However, if you have an average of 10 customers per day, a 100-gallon tank will definitely be the better choice because a tank closer to 50 gallons will need refilling multiple times per day to meet these requirements. 

It’s a good idea to aim to carry enough water with you to clean your average number of vehicles per day, plus an extra one in case you exceed your typical demand. It’s always best to be prepared for every eventuality. 

Frequency Of Water Tank Use 

Not every auto detailing project requires the use of a water tank.

For example, there may be many situations where you travel to a client’s home to detail their vehicle and are able to connect to their water source directly, meaning that you won’t need a tank. 

Take into consideration how many times per day or week you actually need to use a water tank.

If getting out your water tank is more of a rarity for your business than an everyday occurrence, consider whether you really need a 100-gallon tank. 

In fact, if you only need a water tank for a couple of detailing jobs every day, you may prefer to buy a 25-gallon tank with a good return on investment. If you feel that this is the right decision for you, go for it!

The point of this guide is to encourage you to make decisions based on what you know about your detailing business as opposed to following one-size-fits-all instructions.

Purchasing a large water tank when you don’t need one is just a waste of money, and when you’re trying to run a business, the last thing you want to do is throw away your earnings on unnecessary equipment. 

Vehicle Washing Methods 

The way that you approach detailing and washing vehicles will impact the amount of water you need to use, and this, in turn, will play a part in determining the appropriate water tank size for your service. 

Some detailers like to use multi-step processes when washing vehicles. This might involve a pre-wash rinse, followed by foam, then another rinse and shampooing before finally rinsing the vehicle again.

In this example, there are five steps, four of which involve the use of water. This method would require much more water (and a much larger water tank) than if you simply did the shampoo wash followed by a rinse. 

Similarly, if you use three buckets of water when washing a car, you’ll probably want to opt for a larger water tank than if you typically just use one bucket. 

Not every detailer will want to follow such an extensive process when washing a car, though. After all, washing is only a part of detailing.

Therefore, if you prefer to skip some of these steps, go ahead and purchase a smaller water tank that is more in keeping with the steps you tend to follow.

While you’re assessing what your washing process means for your optimal water tank size, also consider your pressure washer’s GPM flow.

You can find this information in the user manual or through the manufacturer’s website, and you can use the measurement of gallons per minute to work out how many minutes of washing a tank of a certain size will last through.

Then, compare this to how many minutes of washing you typically do in a day. 

Your Vehicle Model

Of course, you can’t buy a water tank for the purpose of mobile auto detailing until you know whether it will fit comfortably inside your own vehicle along with the rest of your detailing equipment. 

You will need to think about the size of your vehicle before you can conclude that a specific tank size is right for you. 

If you’re working out of a standard-sized vehicle, we would usually recommend a 50-gallon water tank, whereas a larger vehicle like an SUV or a truck should be able to hold a 100-gallon tank as long as the rest of your equipment doesn’t take up too much space. 

Bear in mind that water tanks don’t come in just one shape! You can find tanks that sit vertically or horizontally, and while some are barrel-shaped, others are rectangular or cube-shaped.

This means that you have plenty of options when it comes to finding a tank that fits comfortably in your vehicle. 

If you’re interested in finding out which water tanks are the best for mobile auto detailing, read on! We’re going to recommend two of our favorite water tanks now. 

Water Tanks For Mobile Detailing: Product Recommendations 

Detail King 100 Gallon Water Tank

Water Tank 100 Gallon - 38.5' x 26.5' x 25' - Mobile Detailing...

The Detail King 100-Gallon Water Tank has been designed with mobile detailing in mind, so you know it’ll be perfect for the job. 

Admittedly, being a larger water tank, this isn’t the most budget-friendly option, but the construction is very high-quality, which means that it’s a durable choice.

For example, the tank is UV-resistant, so you can use it outdoors for hours at a time without worrying about damaging the plastic. 

If you look around the exterior of this tank, you’ll see that there are slots molded around the top, sides, and bottom so that the tank can easily be tied down inside your vehicle.

One of the biggest concerns mobile detailers have when using a larger water tank is that it will slide around inside their vehicle and cause damage to the rest of their equipment, but this isn’t an issue with the Detail King tank. 

This tank measures 25 inches in height. It’s 38.5 inches long and its width is 26.5 inches. Because it’s such a large tank, the cost of shipping is fairly high.

If you can drive to collect it yourself, you’ll save yourself a significant amount of money. 

Water Tank 100 Gallon - 38.5" x 26.5" x 25" - Mobile Detailing...
  • When tank is full, capacity expands to 100 gallons
  • UV Stabilized for outdoor storage
  • Linear polyethylene

WaterPrepared Blue 55 Gallon Water Storage Tank 

Blue 55 Gallon Water Storage Tank by WaterPrepared - Emergency...

If you’re looking for a smaller water tank for mobile auto detailing, we recommend the Blue 55-Gallon Water Storage Tank from WaterPrepared. 

This is a vertical tank that has been designed to fit easily inside most vehicles. The other design elements of the Blue 55-Gallon tank make it perfect for mobile detailing, too.

For example, the cap on top of the tank is large enough to make filling it up an easy task. You can also find a spigot at the base of the tank that you can use to connect a pressure washer, garden hose, or water pump. 

Like the Detail King tank, this tank is made of UV-resistant plastic that won’t be damaged by exposure to the sun or contaminate the water inside.

In fact, this tank will keep the water in such great condition that you could safely drink from it if you needed to! 

This tank measures 30 X 28 X 22 inches, so it shouldn’t be difficult to find space for it in your vehicle. The only issue is that it doesn’t have tie-down slots, so you’ll need to take extra care to make your straps as secure as possible. 

Blue 55 Gallon Water Storage Tank by WaterPrepared - Emergency...
  • ALWAYS BE PREPARED: Be ready to face any water emergency or water...
  • HYGIENIC & SAFE DRINKING WATER: The WaterPrepared barrel is reinforced...
  • STRONG, RESILIENT CONSTRUCTION: Manufactured with a rugged...

Final Thoughts 

If you’re running a mobile auto detailing business, a water tank might be one of the most important pieces of equipment in your toolkit.

That’s why it’s important to consider your choice of water tank carefully, especially when it comes to size. 

The optimal size range for mobile detailing water tanks is 50 gallons to 100 gallons.

The specific size you choose should depend on the size of your own vehicle, how many vehicles you wash on a daily basis, and how much water is used in your chosen cleaning method. 

If you have a smaller vehicle and don’t wash more than 6 vehicles per day, you might want a tank that’s closer to 50 gallons, whereas if your vehicle is of a larger size and you have a lot of vehicles to wash every day, 100 gallons will be more suitable.