
Това е есенцията:
"Due to the much higher exhaust out temperatures of petrol engines (550-750°C) compared with those of modern diesel engines (250-450°C).
Petrol exhaust gasses also contain VERY LITTLE OXYGEN when running stoichiometrically (the amount of oxygen present is the exact amount needed for complete combustion of fuel) and under load.
Diesels burn leaner and have more available oxygen in the exhaust mixture.
For particulates to burn off during a DPF/GPF regen, a surplus of oxygen in the exhaust mixture is needed (so the catalysed oxidation/combustion of the particulates can occur) along with a high temperature in the particulate filter itself (to overcome the activation energy for this combustion reaction).
This means that for a DPF regen, high load is needed to give the required exhaust temperatures for oxidation of the particulate to occur.
Whereas for petrol engines, the exhaust is almost always hot enough for regeneration to occur thus all that is required for regen is a high enough oxygen content in the exhaust mixture for oxidation of the particulate which happens during overrun or low load scenarios. Therefore, GDF's do not require an active regeneration cycle like DPF's as simple everyday driving will do!
Also, particulates from petrol engines are much faster to oxidise than their diesel particulate counterparts. this means that there is much less 'soot loading' in a GPF when compared to a DPF, this means that GPF's are much smaller (GPF volume ? Engine displacement) than DPF's (DPF volume ? Engine displacement)."