Adjustments to new vehicle emissions legislation scheduled for 2009 the ‘Euro 5’ expectations, will make particulate filters as commonplace in diesel car exhausts as catalytic converters are on petrol vehicles.
The purpose is an eighty% reduction in diesel particulate (soot) emissions, but the technology’s not without having problems roadside guidance patrols are presently currently being named to autos with the particulate filter warning gentle illuminated, which normally suggests a partial blockage of the DPF filter.
Obviously, modifications to driving variations may possibly be needed for optimum advantage from these emission-lowering methods.
How do the filters work?
Diesel Particulate filters (DPF) or ‘traps’ do just that, they capture bits of soot in the exhaust.
As with any filter (feel of the bag in your vacuum cleaner) they have to be emptied regularly to sustain overall performance. For a DPF this process is referred to as ‘regeneration’ the accrued soot is burnt off at large temperature to depart only a tiny ash residue. Regeneration may possibly be either passive or active.
Passive regeneration – Passive regeneration requires location routinely on motorway-variety operates when the exhaust temperature is higher. A lot of cars will not get this type of use although so companies have to layout-in ‘active’ regeneration the place the engine management personal computer (Ecu) normally takes manage of the approach.
Lively regeneration – When the soot loading in the filter reaches a set limit (about forty five%) the Ecu can make small adjustments to the gas injection timing to increase the exhaust temperature and initiate regeneration. If the journey’s a little bit end/commence the regeneration may possibly not full and the warning light will illuminate to show that the DPF is partially blocked.
It must be feasible to begin a complete regeneration and very clear the warning light just by driving for ten minutes or so at speeds better than 40mph.
If you ignore the light-weight and keep driving in a comparatively slow, quit/begin pattern soot loading will carry on to create up right up until all around seventy five% when you can count on to see other dashboard warning lights illuminate also. At this stage driving at pace by itself will not be ample and the automobile will have to go to a supplier for regeneration.
If warnings are still overlooked and soot loading continues to increase then the most probably end result will be a new DPF costing about £1000.
Mostly town dependent driving
If your very own automobile use or lease vehicle use is mainly city-based mostly, stop/begin driving it would be smart to pick petrol fairly than chance the problem of incomplete DPF regeneration.
The most widespread type of DPF functions an integrated oxidising catalytic converter and is positioned very close to the motor the place exhaust gases will nonetheless be fairly very hot so that passive regeneration is possible.
You will find not often area shut to the engine although so some makers use a diverse sort of DPF which relies on a gas additive to reduce the ignition temperature of the soot particles so that the DPF can be situated further from the engine.
The additive is saved in a separate tank and is immediately combined with the fuel every time you fill up. Very small quantities are necessary although so a litre of additive ought to deal with around two,800 litres of gasoline, adequate to protect 25,000 miles at 40mpg.
With this type of DPF regeneration will be initiated by the Eu each three hundred miles or so depending on car use and will just take five to ten minutes to total. You shouldn’t recognize everything other than probably a puff of white smoke from the exhaust when the approach is completed.
The AA has observed evidence of DPF programs failing to regenerate – even on autos – that are employed largely on motorways. how often to clean dpf filter pennsylvania is that on cars with a really large sixth gear engine revs are too low to generate adequate exhaust temperature, but occasional more challenging driving in reduced gears must be enough to bum off the soot in this kind of circumstances.
Check out the handbook
If you get or lease a vehicle with a DPF fitted it really is crucial to read through the pertinent segment of the vehicle handbook so that you recognize precisely what actions to take if the warning gentle illuminates and how, if at all, your driving design might need to have to be altered to make sure greatest DPF efficiency and life.