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What Is A One-Box On A Truck? (Explained For Beginners!)

Newbie truckers may not be familiar with all the terms or labels most truckers use. One of these is the one-box. 

As its name implies, it is a single box, obviously found in trucks, but what does it do, and why should you know more about it? Read on to find out more…

Here’s a Quick Answer to What is a One-box on a Truck:

A one-box fitted on a truck is a compact box assembly that contains DOC, DPF, and SCR technologies to treat vehicle emissions. The one-box serves as a diesel exhaust after-treatment system to help trucks comply with the EPA10 emission standards stipulated by the Environmental Protection Agency.

What are the Components of a One-box?

A typical one-box of trucks consists of the four vital components of the exhaust system.

These are the Diesel Exhaust Fluid (DEF), Diesel Oxidation Catalyst (DOC), Diesel Particulate Filter (DPF), and Selective Catalytic Reduction (SCR).

How Does One-box on a Truck Work?

The one-box is fitted on the exhaust side of the engine and works by cleaning the vehicle’s exhaust gasses emitted to the environment.

The design intention of this system is to meet the EPA10 emissions regulations by reducing harmful pollutants such as carbon monoxide, hydrocarbons, and particulate matter released by the exhaust.

It also features improved thermal encasing of exhaust energy to produce a more efficient muffler. In that case, the truck will increase flexibility and fuel capacity.

The one-box encases several air quality control technologies, such as the diesel exhaust fluid injector, diesel oxidation catalyst, diesel particulate filter, and the selective catalytic reduction system, all in one compact box.

The different systems play a role in cleaning the exhaust gases of the truck.

The DEF lessens the nitric oxides or NOx gases that the diesel engine creates.

The DOC is responsible for the oxidation reaction or the conversion of hydrocarbons and carbon monoxide (CO) into water vapors and carbon dioxide (CO2). It also breaks down the pollutants in the diesel engine’s exhaust stream.

The DPF functions by capturing the diesel particulates that come out of the engine. The process of capturing the particulates happens in two ways, which are active and passive regeneration. 

The continuous process will then accumulate the particulates in the filter, which can be removed once the DPF is cleaned through the restoration process.

And lastly, the SCR is where the Nitrogen Oxide gases and Ammonia react to form Nitrogen and water vapor.

This typically lessens the cycle of active regeneration. On the other hand, active regeneration can happen anytime after the engine starts working and the exhaust temperature increases.

Do All New Trucks Come with a One-box Fitted?

Almost every new truck released by famous brands, such as Volvo, will now have a one-box fitted in its system.

It is an after-treatment system that combines the DPF, SCR, and DEF injector components into a single unit. In this way, there is more weight and space.

For older ones looking for a new replacement, there is an available aftermarket one-box you can use. One example will be the Dinex, which Freightliner and Western Star trucks can use.

When Would You Need a One-box to be Fitted on Your Truck?

If the DPF of the exhaust after-treatment system of your truck becomes clogged with ash, soot, or other tiny particles, it can cause the DPF to crack and fail.

Thus, it is the best time when you need a one-box to be fitted on your truck.

But regardless of whether the DPF gets faulty, you will still need to replace it over time if it is already too old. That way, you can still guarantee that the exhaust system will work okay.

What Maintenance Does a One-box System Require?

The most effective maintenance you can conduct for a one-box system is monitoring system condition.

It is similar to preventive maintenance, wherein you diagnose the issue before it causes a significant problem in your truck’s system.

A full DPF service or cleaning will also help to keep the truck functioning well for several days. There are different ways you can clean a DPF, such as by air, liquid cleaning, or thermal processes.

You should refrain the cleaning and leave it to professionals since the wrong cleaning method can cause the One-box to overheat, resulting in poor performance of the vehicle.

How Long Does a One-box Typically Last?

A one-box can usually last for about 600,000 miles. However, some trucks can reach up to 800,000, which is rare.

Even if you think the one-box in your truck can still work well after exceeding its average mark, which is 600K miles, you may already consider replacing it with a new one.

A typical cost of a new one-box is about $9,000. At first glance, it is expensive, but it is a good value since you can use it for longer.

What are the Advantages of Having a One-box on a Truck?

Over time, the DPF of your truck will have ash buildup and cause some issues on your vehicle. It is also an indication for you to remove and clean it.

Since removing and cleaning the DPF is tedious, you may want to make the process easier and faster. Thus, you can rely on the advantages of what One-boxes can offer.

First thing, the One-box can solve low Nox conversion issues in OEM. It is a common issue that usually happens when the DEF starts to build up in the SCR.

In addition, the One-box compact design also provides more space in the frame rail. Thus, it produces better flexibility for trucks with APUs, larger fuel tanks, and other accessories or components of the chassis.

The One-box design also lessens the installation time on the assembly line, giving more space for weight saving.

There are still many drivers who do not understand the complexity of the One-box emission control system. Some may find it as an additional expense or just an extra feature.

Overall, this after-treatment system will benefit the diesel engine, improving the performance and reliability of your truck.

What are the Disadvantages of Having a One-box on a Truck?

The only disadvantage you may consider in having a one-box in your truck is replacing the entire system, even though only one component has an issue.

You may also consider allotting more time and money for the diagnosis and service of the truck since the One-box and its repair or replacement are pretty expensive.

Other than that, you may not experience any inconvenience.

If you decide to remove and not use one for your truck, you will face many cons, such as upfront cost, failing to comply with emissions laws or inspections in certain states, warranty issues, etc.

As you weigh the advantage and disadvantages of having a one-box fitted in your truck, you will choose to have it installed in your truck’s system instead.

Do Truck OEMs Manufacture Their One-box?

Some truck companies do, while others may have collaborated with other manufacturers.

Volvo Trucks manufactured their One-box Exhaust Aftertreatment System or One-box EATS.

For the Freightliner and Western Star trucks, the Dinex manufacturer offers a One-box exhaust solution with a three-year warranty for their American aftermarket.

Who are the Leading Manufacturers of One-box?

We can consider Dinex and Roadwarrior as the current leading manufacturers of One-box.

Dinex releases a new patent for their One-box. It aims to be used for Freightliner trucks, a famous truck brand in the U.S.A., and the Western Star.

Truck models from these companies with a 2010 year model and using DD13, DD15, or DD16 engines will be the most that can benefit from this One-box exhaust after-treatment system.

On the other hand, the Roadwarrior also developed the first One-box intending to help more vehicles reach a million of mileage from their diesel engine.

They offer peak emissions control and engine efficiency on their components to guarantee the best performance for your truck.

The Roadwarrior claimed to be the best-selling One-box aftermarket in the United States from 2019 to 2020.

What is the Cost of Installing a One-box on your Truck?

The total cost of installing a one-box on your truck can amount to $15,000 to $20,000.

For the parts alone, you may have to spend at least $9,000 to $13,000.

If you find a mechanic offering a more affordable labor fee, you can lessen the total expense by a thousand dollars.

Best One-box Systems in the Market

As mentioned, both the Dinex and Roadwarrior stay top in the competition that offers the best One-box systems in the market.

Both of them are still further in development. Thus, you can expect more from these two know manufacturers to produce the most reliable systems for exhaust after-treatment systems.