DPF deletion, MOT's and the law?

Jonnycoupe said:
You have over simplified that just a little....

Revving the engine?

DPF regen requires relatively high speed cruising to provide adequate load and hence heat energy. I know of no system that does high speed idle for regen, the airflow running over the car is very usefuel when dealing with the external temps they get to.

For example its the high heat energy in the DPF thats leading to EGR systems that take exhaust after the DPF and then run through a larger low pressure EGR cooler before getting back into the intake manifold. Otherwise under regen its just too hot to use pre DPF.

Diesels are a nightmare. I will never buy one with my own money :p
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I saw some re-gen videos where the car was stationary and holding the revs at about 4K for 5 minutes or so. One of a 1.6TDCI Focus, one of a Zafira 2.0 CDTI, one of a Brera 2.4JTDM. Were they "forced" regens then? And normally it would be done when the car is moving?

Blackhawk mentioned his TT doing the regen after he pulled onto his drive, so I assumed that would have been stationary too ?
 
Those were forced regens, you won't ever notice a car doing a regen. I'm
Sure some retard the timing to increase temperature but no car in the world would idle at 4k for 5 minutes... I'm surprised that even needs to be explained :/

You may as well tell us what car you're talking about buying, but will never actually buy, so we can round off this thread
 
Acme said:
Blackhawk mentioned his TT doing the regen after he pulled onto his drive, so I assumed that would have been stationary too ?
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Yes I can only tell because I can see the idle revs hold at just over 1000rpm. The car also sounds a bit different when driving around with the DPF doing a regen. You can definitely feel the heat from the exhaust if standing directly behind. Same with the A1 I had.

Maybe the system in Fox's BMW works differently I dunno.
 
iaind said:
Those were forced regens, you won't ever notice a car doing a regen. I'm
Sure some retard the timing to increase temperature but no car in the world would idle at 4k for 5 minutes... I'm surprised that even needs to be explained :/

You may as well tell us what car you're talking about buying, but will never actually buy, so we can round off this thread
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With Vauxhall cars at least the regen can run at idle, our old Zafira would do a regen at idle, easily seen from the trip computer where the fuel consumption would be at 1.1 gallon an hour rather than 0.2 gallon an hour. If you get out the car the exhaust note is also slightly deeper. On the move the range drops rapidly during a regen and the mpg drops to low 20s.

You can tell with the F10/11, I had a demo car do it same signs really plus the autobox can also drop a gear to get the revs up surprised Fox hasn't noticed this in his ownership.
 
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Another note too add regarding the soot.

The soot doesnt actually come out the back of the exhaust during a re-gen. The whole point of the dpf is to keep the soot inside, then re-gen the dpf by heating it up to burn off the soot and this turns the soot into ash and then remains inside the dpf itself, which is then why a dpf is a serviceable item and WILL need replacing at some stage in its life.
 
Yes forced regen to get rid of a check engine light/DPF code will be monkeys revving at idle rather than taking it for a proper drive. Higher speed idle as part of the engine cal is just to hold heat in the brick ready for a proper regen event.
 
I notice the MPG drops to 30 or 40 according to the OBC during a regen rather than 60-70 it normally is.

I don't mind DPFs, it means cleaner more environmentally friendly cars, my current car already meets the Euro 6 standard even though its 3 years old.
 
I'm tired of constantly having to turn on my re-circulate air system when smelling diesel exhaust fumes all the time and desperately attempting to reduce the amount of it I breath in.

Hopefully when the VED system is overhauled, diesel will end up less attractive to the average car buyer.
 
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