Document ID: chunk:federal_register_of_legislation:F2009C00402:body:0:p26
Version: federal_register_of_legislation:F2009C00402
Segment Type: other
Provision Reference: 
Character Range: 72615–75485

sulfur levels typical of the fuel used by the target vehicles in normal use.

 5. The DOC is demonstrated (by means of an acceptable durability test or in-service testing) to remain effective over the life of the vehicle. The DPF is demonstrated to remain effective over the life of the vehicle if maintained correctly.

 6. The DOC/DPF/PFT does not significantly increase vehicle noise in the target vehicles when tested in accordance with the requirements of ADR28/01.

 7. The DOC/DPF/PFT does not significantly increase exhaust back pressure in the target vehicles to a level outside the manufacturer's specification.

 8. The device shall be designed based on sound and proven scientific principle.

 9. The device shall not require any fuel-additive to support its operation, nor shall it be an additive, by itself, for consumption in the combustion process of the engine.

 10. The device shall not cause harmful effects to the engine of a vehicle to which it is installed or unduly affect the performance of the engine.

 It is the DOC/DPF/PFT supplier/manufacturer's responsibility to demonstrate that their aftertreatment device complies with the above requirements. The tests shall be carried out by independent and appropriately certified third party laboratories.

 Note that there may be a potential for NOx (and NO2) emissions to increase with the retrofit of some particle traps which use oxidation catalysts and that jurisdictions may wish to assess the relative benefits of a retrofit program within their jurisdictions beyond particle emission considerations.

3.2.2   Selection of appropriate retrofit technology

 Exhaust temperature determines the PM reduction efficiency of DOCs. The NSW Diesel Exhaust Retrofit Program has shown that PM reduction efficiency improves, as temperature increases, up to about 300 C.  Over 300 C the efficiency decreases.

 DPFs periodically require high exhaust temperatures, so that the carbon trapped in the filter, can be burnt off.  Failure to burn off the carbon will cause the filter to become blocked and will affect engine performance. Typically, exhaust temperature should exceed 260 C for at least 40 percent of the duty cycle.

 It is understood that DPFs may not perform well in pre-Euro 2 emission standard vehicles, and that neither DPF nor DOC should be fitted to vehicles burning excessive amounts of oil.

 Overall cost effectiveness of DPFs compared to DOCs appears to be similar. DPFs are around three times more efficient than DOCs in terms of PM reduction but also cost around three times more. The need for extra maintenance and possible price increases for DPFs may swing the cost benefit balance towards DOCs in the future.

 PFTs do not have the exhaust temperature restriction and will not block up if the duty cycle requirements are not achieved. With PFTs, there is a reduced