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Car Aftertreatment Service And Maintenance: How Does It Work?

Car Aftertreatment Service And Maintenance: How Does It Work?

We know many sim racers own and drive real cars, are you looking after your car with service and maintenance correctly?

We know as times are moving forward, it is extremely important to look after your car with a service and maintenance. When we look at Racecars as an emissions example, the numbers add up and the reality is real.

Racecars are some of the most emission-intensive vehicles in use right now. For example, one NASCAR race involving around 40 stock cars can emit as much as 20 lbs of carbon dioxide per gallon of gas burned. Given that these cars have an abysmal fuel economy of just 5.0 mpg, the practice laps and actual race will burn an average of 6,000 gallons.

The emission problem even got to the point that the Environmental Protection Authority (EPA) once attempted to introduce an amendment that would ban conversions of cars into dedicated racing vehicles. The fight to protect racecars continues as of this writing, with the pro-racecar Recognizing the Protection of Motorsports Act introduced in Congress last year.

Nevertheless, it’s inspired the motorsports industry to find ways to keep racing emissions to a minimum. One technology that may help is the aftertreatment system and its intricate means of treating emissions even further. Here’s a look into such a device and how to keep it functioning:

Total Breakdown

Whether running on gasoline or diesel, cars primarily emit the same harmful stuff into the air. Usually, catalytic converters are enough to prevent the majority of toxic gas emissions from escaping. But, the constant combustion and emission might overwhelm the catalytic converter when driving for hundreds of laps.

An aftermarket system can give it a much-needed helping hand, especially for engines equipped with turbochargers. It features plenty of parts, most of which you can buy from suppliers such as Cummins supply stores, but you mostly need to understand four fundamental ones. These are:

  • Oxidation Catalyst

As soon as the engine exhaust enters the aftertreatment system, the first thing it’ll encounter is the oxidation catalyst. This first layer can break down as much as 40% of particulates, 75% of hydrocarbons, and 60% of carbon monoxide (as per EPA estimates). 

  • Particulate Filter

The particulate filter is just behind the oxidation catalyst, which can trap more particulates and other harmful matter. It utilizes heat to create less harmful elements, like carbon dioxide, through bonding carbon-based particulates with oxygen. 

  • Mixer And Urea Injector

As the exhaust passes halfway through the aftertreatment system, it gets injected with a dose of ammonia. Experts estimate the proper dose to be between 100 µm and 30 µm. The system draws ammonia from a reservoir located further back.

  • Selective Catalytic Reduction (SCR) Catalyst

The SCR catalyst is at the end of the aftertreatment system, which forces the nitrogen oxide in the exhaust and urea to undergo a chemical reaction. The exhaust leaves the system as pure nitrogen and water vapor.

Keeping It Working

The impressive technology aftertreatment systems feature comes at a hefty cost. A single unit can cost at least USD$7,000, so you’d want one to remain functional for as long as possible. Regular maintenance is the only way to do so. It isn’t that hard to see why that’s the case.

Take particulate filters, for example. Like the HEPA filters in HVAC systems, particulate filters can get clogged with the stuff they’re filtering out over time. Sooner or later, they won’t be able to keep the particulates from escaping into the air. Particulate-induced asthma is no joke.

Another case is the limited supply of ammonia for the mixing process. While the tank can hold between 15 and 50 gallons, good for over 6,000 miles, constant races can make topping up a more frequent affair. There’s also the matter of injecting insufficient ammonia into the exhaust, which can cause some nitrogen oxide to go past SCR untreated.

Maintenance experts say it’s crucial to pay attention to warning lights. The aftertreatment system has a sensor for nearly every component that can alert drivers and maintenance personnel of potential or existing issues. They also advise against waiting for the whole thing to fail before taking action, as it’ll lead to costlier repairs or replacement.

Due to their purpose, the particulate filters are among the most serviced components in an aftertreatment system. A brand new filter may be a good option, but experts say cleaning, if possible, is better. The cleaning process can either involve a liquid wash or bake-and-blow (although some service centers have stopped offering the latter since the former is more effective).

If you want to reduce the burden on an aftertreatment system, topping up with engine fluids that produce less particulate matter can help. For instance, additives in engine oil account for almost 90% of the stuff that particulate filters trap. As such, you can settle for engine oil that produces less of it to extend the filters’ service life.


There’s no reason for the motorsport scene to be unaware of the emissions their races release into the atmosphere. The existence of Formula E is one indication, but current technologies such as aftertreatment systems are game changers. When properly serviced, they can make future races more exciting without harming the environment.

Douglas Moseley

Douglas Moseley

Douglas Moseley has worked within the media sector for several years. His outlook sets out to be promotional and engaging content for an alternative audience.View Author posts

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