Strange! When I took mine back for its first service, I asked about the dpf and was told: "You don't have one if you have AddBlue."
I work for a German company. We indeed make an engine that uses only and SCR (adblue) system. The exhaust system will look like a dpf. But it is a catalyst for the reaction to occurr to reduce high NOx output.
Again heat is required. An SCR engine runs hotter than dpf's. But this is done by loading the engine with a flap in the exhaust to maintain an exhaust temp of 300 DegC +or- 20. SCR injection can then be done and the NOx brought to a legal limit. You will get puffs of smoke on these engines. Other items to note. Single turbo and less sensors. So potentially less costs. Much easier to work on. It's been out a long time on the trucks. So is solid technology now.
To touch on some of the other comments and thoughts.
We also make a dpf system. As said we use a compound turbo arrangement with Egr and dpf.
A dpf engine runs cold in engine terms. Is also not efficient due to egr and engine timing. Hp for hp dpf against scr the scr is more powerful. So like a cold fire. It makes smoke. So the dpf catches the smoke. To clear the spot from the smoke. The exhaust temps need to be 350degC for passive regeneration. Regeneration is 650degC but this needs fuel injection into the exhaust to achieve. But can't go ahead without the temp reaching the above. So now you see why driving or loading the engine creates the above.
More points to mention. If you have smoke on a dpf tailpipe it's cracked. So I wouldn't not buy it. You will see steam from these on most winter days. Shorts runs, long term idling will make the Regen times more frequent. Ok if you do long runs in between or get the engine loaded and creating exhaust heat.
From the day a car is built it's filling the dpf up. As already said Regens clean it. But it still leaves ash in there. So eventually they will need replacement. In my experience they vary from a few years to some that haven't been changed in nearly 10.
Another aspect to consider is engine oil type. The wrong engine oil will contribute to filling a dpf up too.
We have a dpf car. It doesn't worry me. The wife drives 13miles taking 40mins everyday. Been ok. It gets good runs at weekends/holidays and she has a heavy right foot.
I use an 06 hilux. You forget how bad fumes are off these. But it's ok on short runs.
As said else where get a petrol if not going far or achieving the above.
Hope this long post helps. I'm a boring sod who loves engines.
