Why are direct injection petrol engines a particular problem?

I'd have thought this would give a more complete combustion of the fuel compared to a non direct injection types.

Its not really hot off the press news, its been known for some time that DI petrols would be fitted with particle filters in the future but it looks like VW are as said above getting ahead of the game in an attempt to get some good PR for a change.

I read up on petrol particle filters when they were first mentioned and it appears they are very different form diesel particle filters. Since petrol exhaust gasses are much hotter than a diesel they regenerate constantly rather than needing specific regens like a diesel. They are also much simpler and cheaper than DPF's so I don't think those of us who have accepted we are in the 21st Century have anything to worry about.

Remember the doom mongers who said the petrol was dead when cats became law. In the past 25 years I have only known one friend/aquaintance/work colleague need to replace and that was on a 15 year old 60,000 mile one old lady owner Corsa he bought after passing his test.

I intend to carry on driving modern cars as my main form of transport so adopting new technology is something I accept and applaud especially when it has benefits that go futher than the actual vehicle owner.