Let’s dive into some theory.
A diesel particulate filter (DPF) is designed to remove soot particles from the exhaust gases of a vehicle’s engine. Its main function is to reduce pollution.
There are two types of DPFs: closed and open. Since most modern vehicles have closed DPFs, we will focus on them.
The DPF consists of a cellular structure made of silicon carbide or cordierite. It has numerous parallel channels with wall thickness ranging from 300 to 400 micrometers.
The adjacent channels are closed at both ends with ceramic plugs, forcing the exhaust gases to pass through the porous ceramic walls where the soot particles get trapped.
The filtration efficiency of the DPF can reach up to 95%.
NOW, LET’S TAKE A LOOK AT THE PROCESS FOR BETTER UNDERSTANDING.
It’s logical that when too much soot accumulates, the filter loses its efficiency. But there’s a solution: regeneration. This process involves burning off the accumulated soot.
To initiate regeneration, the exhaust gases need to reach a temperature that allows for soot combustion, which is around 600 degrees Celsius. This temperature is achieved by injecting additional fuel (along with other manipulations).
To initiate regeneration, the exhaust gases need to reach a temperature that allows for soot combustion, which is around 600 degrees Celsius. This temperature is achieved by injecting additional fuel (along with other manipulations).
Regeneration occurs when you are driving at a constant speed between 60 and 100 km/h. It cannot happen when you are stuck in traffic or idling since the necessary temperature cannot be reached. Regeneration may be accompanied by the emission of a bluish smoke from the exhaust.
NOW, LET’S ADDRESS THE MAIN QUESTION: THE LIFESPAN OF A DPF.
When you press the gas pedal for acceleration, the highest amount of soot particles is emitted because more fuel is being injected.
More fuel equals more soot. When you drive at a constant speed without accelerating, the emission of soot particles tends to decrease.
Therefore, those who primarily drive in the city (accelerate, brake, accelerate, brake) will experience faster clogging of the DPF and have fewer opportunities for successful regeneration. On the other hand, those who drive on highways, smoothly accelerating to a constant speed of around 100 km/h, will experience minimal soot buildup and always have a better chance of complete regeneration.
Predicting when the filter will become completely clogged is quite challenging since it largely depends on individual driving habits.
More fuel equals more soot. When you drive at a constant speed without accelerating, the emission of soot particles tends to decrease.
Therefore, those who primarily drive in the city (accelerate, brake, accelerate, brake) will experience faster clogging of the DPF and have fewer opportunities for successful regeneration. On the other hand, those who drive on highways, smoothly accelerating to a constant speed of around 100 km/h, will experience minimal soot buildup and always have a better chance of complete regeneration.
Predicting when the filter will become completely clogged is quite challenging since it largely depends on individual driving habits.
By the way, if you see a message on your onboard computer indicating a clogged DPF, don’t rush to the service center. Instead, drive at a constant speed between 60 and 100 km/h for approximately half an hour. If this doesn’t resolve the issue, then it’s time to visit the service center.
