Petrol engine particulate filters

Engine, Exhaust, Drivetrain, ECU Issues and Fixes
Deleted User 887

Post by Deleted User 887 »

Lots of articles on Google for petrol engine particulate filters (GPF), copy of post below from Pistonheads www.pistonheads.com/gassing/

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).

Various other articles:
GASOLINE PARTICULATE FILTER (GPF), www.greencarguide.co.uk/features/gasoli ... filter-gpf
Volkswagen Group to fit particulate filters to all petrol engines from 2017, www.autocar.co.uk/car-news/industry/vol ... gines-2017

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Post by Bigboyrolo »

MEO wrote: Sat Jan 27, 2018 12:53 pm Lots of articles on Google for petrol engine particulate filters (GPF), copy of post below from Pistonheads www.pistonheads.com/gassing/

Due to the much higher exhaust out temperatures of petrol engines (550-750°C) compared with those of modern diesel engines (250-450°C).

Various other articles:
GASOLINE PARTICULATE FILTER (GPF), www.greencarguide.co.uk/features/gasoli ... filter-gpf
Volkswagen Group to fit particulate filters to all petrol engines from 2017, www.autocar.co.uk/car-news/industry/vol ... gines-2017
Technically interesting and environmentally sensible but I fnd it curious that Porsche feel the need to cease petrol engine prodction for many months in order to modify their engines. Surely the development work could be going on and modifications made while in production. I sense interference from EU legslators.
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Post by Mike and his Macan »

From what I understand from 2020 any car that’s sold buy the manufacturer that is unable to meet the emissions it has stated , is to be fined $ 29,000 per vehicle sold... mybe this could answer some questions.
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Post by Paul »

To continue the theme, I see in this months “Christophorus” there is a short piece on gasoline particulate filters.

Interesting, but the last paragraph does give an insight into possible problems;

“With long periods of frost and a lot of short drives, a somewhat longer drive can be necessary for regeneration” ........sound familiar......??
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Post by ScotMac »

Paul wrote: Sat Oct 20, 2018 10:42 am To continue the theme, I see in this months “Christophorus” there is a short piece on gasoline particulate filters.

Interesting, but the last paragraph does give an insight into possible problems;

“With long periods of frost and a lot of short drives, a somewhat longer drive can be necessary for regeneration” ........sound familiar......??
I read the article and did wonder if petrol cars are going to follow diesel .............unsuitable for city driving / short journeys :roll: :roll: :roll:
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Post by VanB »

ScotMac wrote: Sat Oct 20, 2018 11:29 am
Paul wrote: Sat Oct 20, 2018 10:42 am To continue the theme, I see in this months “Christophorus” there is a short piece on gasoline particulate filters.

Interesting, but the last paragraph does give an insight into possible problems;

“With long periods of frost and a lot of short drives, a somewhat longer drive can be necessary for regeneration” ........sound familiar......??
I read the article and did wonder if petrol cars are going to follow diesel .............unsuitable for city driving / short journeys :roll: :roll: :roll:
Maybe that's the point - if you live in a city your only viable option is an EV?
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Post by Mike and his Macan »

So neither petrol or diesel doesn’t work for short journeys when fitted with these filters , although it’s to early to tell in regards to the GPF , well at least we can trail them out for them , makes perfect sense. This is one of the reasons I took the opportunity to buy the cayman before the filters where fitted, I’m thinking it will be sometime before I’m convinced to buy another petrol car fitted with these things. The irony is that I bought a petrol because I’m now doing short journeys.. and soon in cold Weather!
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Post by GMAN75 »

VanB wrote: Sat Oct 20, 2018 11:32 am
ScotMac wrote: Sat Oct 20, 2018 11:29 am
Paul wrote: Sat Oct 20, 2018 10:42 am To continue the theme, I see in this months “Christophorus” there is a short piece on gasoline particulate filters.

Interesting, but the last paragraph does give an insight into possible problems;

“With long periods of frost and a lot of short drives, a somewhat longer drive can be necessary for regeneration” ........sound familiar......??
I read the article and did wonder if petrol cars are going to follow diesel .............unsuitable for city driving / short journeys :roll: :roll: :roll:
Maybe that's the point - if you live in a city your only viable option is an EV?
Let's extend that thought. Suppose you live in a city and suppose EVERY vehicle is swapped to an EV. Include buses, HGVs, taxis...the lot. Assume the infrastructure exists as well. Now, that does nothing to address the real cause which is congestion and traffic management. I feel all these ad hoc bolt ons to modern engines are knee jerk reactions by governments trying to treat a symptom rather than the underlying cause. It's classic f*ckery...please excuse the language.
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Post by Paul »

As usual, it all depends what they’re measuring...currently it’s NOz and particulates (because diesels have reduced the CO2 bit which was being measured previously!)

When they reach their targets for that, they’ll start to measure congestion and no doubt f*ck that up too!

Like dissuading drivers out of city centres with various tolls.....but not providing any viable alternative means of transport into said city centre.
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Post by SAC1 »

Ah! So the turn of the petrol heads to have pf clogging anxieties! :twisted: :evil:

Still when they get around to legislating against tyre crumb and brake dust particulate pollution we'll all be f""ked. :oops:

That is until Elon invents the personal use BE helicopter..... :idea:
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