In recent years, we have been hearing more and more about Particulate Filters not only in diesel but also in gasoline-powered vehicles. These systems, known as GPF (Gasoline Particulate Filter), are increasingly found in new cars that comply with strict Euro 6d-Temp or even higher emission standards. But why have these filters suddenly started being installed in gasoline engines? What is their actual purpose, what benefits (or drawbacks) do they offer, and how do they differ from the DPF designed for diesel vehicles? In this article, we will discuss in detail what GPF is and how it relates to modern gasoline technologies.
GPF (or OPF – Otto Particulate Filter) is a gasoline particulate filter designed to trap soot and other fine particles generated during gasoline combustion. While historically particulate matter issues were more associated with diesel engines, advanced direct injection gasoline systems (Direct Injection) can also emit a significant amount of fine particles – especially under intense operation at higher temperatures.
Discussions about GPF became more active when Euro 6c (and later Euro 6d) standards significantly tightened the permissible levels of fine particulate matter (PM) for gasoline engines. Soot emissions are particularly noticeable in engines with direct fuel injection, where unburned fuel particles can form microscopic soot deposits. GPF acts as a barrier, trapping these particles and preventing them from entering the atmosphere.
The operating principle is quite similar to that of a diesel DPF: a special porous ceramic or similar resistant alloy structure traps soot particles. The accumulated solid particles are later oxidized or regenerated during the combustion process at elevated temperatures, thus cleaning the filter and allowing it to maintain sufficient flow. The difference between gasoline and diesel filters is that gasoline engines often naturally reach higher temperatures, so additional active regeneration (as in diesel engines) may be less frequently required.
In theory, installing a GPF introduces an additional filter in the exhaust system, which can cause slight backpressure. However, in modern designs, this backpressure is usually minimal and does not significantly affect the engine's performance. This is because gasoline engines (especially those with direct injection and turbos) are designed with GPF in mind, and their ECU (Engine Control Unit) precisely adjusts combustion and exhaust to meet emission requirements without significant loss of performance.
On the other hand, if the GPF becomes clogged for some reason, the exhaust gases may experience higher backpressure, which typically manifests as engine weakness, possibly even triggering a “Check Engine” warning. Such cases are not common but are often associated with improper engine tuning, overly rich fuel mixtures, or, in rare cases, prolonged driving at low temperatures and short distances (where the filter does not reach the required temperature for regeneration).
Turbocharged gasoline engines – one of the fastest-growing areas in terms of efficiency and power enhancement. Many fear that any additional filter will "choke" the turbo, increase lag, or reduce maximum power. The reality is that manufacturers already design exhaust systems with GPF in mind. Since gasoline combustion temperatures and exhaust enthalpy are somewhat different from diesel, GPF construction becomes simpler – the filter even regenerates much faster than DPF in diesel engines.
The bigger challenge here is for tuning enthusiasts who want to maximize the potential of a turbocharged engine. If you want to increase exhaust flow, a dilemma arises: sport catalytic converters, larger diameter exhausts, but then there's the GPF, whose removal on legal roads is usually prohibited (as with DPF in diesel engines). However, there are performance GPF solutions that meet emission requirements while also providing greater airflow, though they are often more expensive and require ECU reprogramming.
Key differences between GPF (gasoline) and DPF (diesel) arise from the characteristics of the combustion processes:
With the introduction of increasingly strict emission standards (e.g., Euro 7), GPF has become or is becoming a standard component in almost all gasoline-powered vehicles with direct injection technology. Manufacturers, responding to market demands to maintain power reserves and driving pleasure, are continuously improving GPF designs to make them as flow-efficient as possible and less restrictive to exhaust flow. Meanwhile, the tuning sector is focusing on legal “performance GPF” solutions that combine environmental compliance with greater exhaust flow.
GPF, also known as the gasoline particulate filter, is a response to increasingly stringent air pollution regulations, similar to DPF in diesel engines. While initially many believed that gasoline engines were "cleaner" and did not require such filters, modern direct injection solutions have shown that some soot is indeed formed, especially when increasing power or turbocharging the engine. GPF effectively traps these particles, and due to the higher combustion temperatures of gasoline, regeneration often occurs more smoothly and easily than in diesel engines.
Automotive tuning and manufacturer engineering are already seeking ways to balance power, efficiency, and emission requirements so that GPF does not become an obstacle to excellent vehicle dynamics. The most important thing is proper operation, regular maintenance intervals, and the use of high-quality fuel and lubricants. This way, both the GPF and the engine can perform their tasks, maintaining great driving pleasure while meeting environmental standards.