Fleet Hire Limited is an established, independent medium sized vehicle management business that focuses on supporting the national and local needs of fleet operators.
Diesel Particulate Filters – a Fleet Hire Guide.
Almost all diesel vehicles now come with a diesel particulate filter, which can reduce diesel soot emissions by as much as 80%, and helps meet current European emission regulations.
These filters work by collecting the sooty emissions during normal running, and then burn the collected emissions off at high temperature whenever the exhaust temperature is high enough – usually this burn off occurs during motorway running. This is called “passive regeneration”.
Passive regeneration doesn’t always occur frequently enough, so once the soot level reaches a certain level (about 45%) the vehicle’s ECU can adjust the fuel injection timing to increase exhaust temperature – “active regeneration”.
If your journeys are too stop-start, even active regeneration may not be enough, and the vehicle’s DPF warning light will come on. If this occurs, the DPF can be cleared by driving for a short while at high revs – over 3,500 will be effective. If you don’t do this, then the soot loading in the DPF continues to increase, and at levels over 75%, it’s likely that an expensive replacement DPF will be required – costing around £1000 and causing your vehicle to be off the road.
On cars with a particularly high sixth gear even motorway driving may not be enough for passive regeneration to occur, therefore it’s recommended to drive hard in low gears occasionally even if you’re a regular motorway driver.
For more information call our driver helpline on 0844 85 45 123