Which strategy is most likely to be used for the passive regeneration of a catalyzed DPF?

The most effective strategy for the passive regeneration of a catalyzed Diesel Particulate Filter (DPF) involves driving at speeds above 45 mph for a duration of 20 minutes. This method is crucial because passive regeneration relies on the natural increase in exhaust temperature that occurs during highway driving, which facilitates the oxidation of soot particles accumulated in the DPF.

When the vehicle operates at higher speeds, the exhaust temperature rises significantly, exceeding the levels required for the catalytic materials within the DPF to initiate the regeneration process. During this phase, the catalyst helps convert the accumulated particulate matter into gases like carbon dioxide and water vapor, effectively cleaning the filter without requiring any additional active measures.

Other methods, such as idling or less speed-focused driving, do not generate sufficient thermal conditions for effective passive regeneration. While driving moderately above 30 mph may contribute to some degree of soot oxidation, it typically lacks the heat and time necessary to achieve a thorough regeneration cycle. Increasing fuel flow can lead to higher temperatures but is not a standard method for passive regeneration since it may also negatively affect fuel efficiency and emissions. Hence, driving above 45 mph for an extended period is the ideal strategy for passive filtration cleaning in this context.