Car, Truck and Bus - ITEM 02 - EMISSIONS
Base Directive: 715/2007/EC
Base Regulation: 83
715/2007/EC (as amended) covers passenger car (M1, M2) and commercial vehicle (N1, N2) emissions. For light duty vehicles, there are 6 tests prescribed therein which are as follows:
Type I: Cold start tailpipe emissions test. A production representative vehicle is tested on a dynamometer. The driver must follow a trace and the vehicle’s emissions are collected and analysed. This test is repeated 3 times unless the vehicle’s emissions are less than 85% of the limit values. If the emissions are between 70-85% of the limits, only two tests are required. If the vehicle’s emissions are less than 70% of the limit, only one cold start test is required.
Type II: Idle CO test (PI (Positive ignition) engines only). The CO concentration at the tailpipe is determined at low idle and at high idle.
Type III: Crankcase ventilation test (PI engines only). The pressure in the crankcase is measured at idle and under load (at 50kph in third gear). A vacuum must always be present to ensure oil vapours are not emitted from the engine crankcase.
Type IV: Evaporative emissions test (PI vehicles only). The vehicle is driven on a type 1 drive cycle, and then enclosed in a SHED (Sealed Housing for Evaporative emissions Determination) which measures the HC concentration of the air within its enclosure. This measures the evaporative emissions from a parked vehicle in the hour after being driven. The vehicle is then subjected to a 24 hour ambient heat cycle to simulate the evaporative emissions from a parked vehicle in a warm climate (range 20-35°C).
Type V: Durability test. The Type V test is performed as measure of the durability of anti pollution devices for both PI and CI (Compression ignition) vehicles. Typically, pollution control devices are artificially aged to simulate how well they would perform after 160,000 km use. Emissions tests are performed on a vehicle fitted with a new pollution control device, and compared with the emissions of the same vehicle when fitted with an aged exhaust. This allows the calculation of deterioration factors (DF) which are used when calculating the engine emissions in a type I test. Alternatively, DF values assigned in the legislation can be used.
Type VI: Cold room tailpipe emissions test (PI only). This test is run in the same manner as the Type I test, except it is conducted in a room with an ambient temperature of –7 degrees Celsius. This only applies to PI engine vehicles as (compared to CI engine vehicles) they require significant mixture enrichment for a cold start.
Other tests: OBD family demonstrations are required to verify that the vehicle’s On Board Diagnostics are monitoring the vehicle’s performance. This aims to ensure that that the driver is notified appropriately and the prescribed emissions limits are not exceeded when component failures occur
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