2005-06 In-Service Vehicle Testing Programme

Carbon Dioxide Emissions and Fuel Consumption. Although there are no mandatory in-use compliance requirements for fuel consumption and Carbon Dioxide (CO2) emissions measurements, these parameters are subject to Conformity of Production requirements for new vehicles. Whilst these requirements do not strictly apply to in-use vehicles, the fuel consumption and CO2 Emissions measurements from this programme have been assessed against the conformity of production requirements to give an indication of whether in-use vehicles differ significantly from the type approval measurements. For CO2, an initial sample of three vehicles is tested and the test statistic defined in directive 80/1268 EEC (as amended) is calculated. By comparing the test statistic with the Pass and Fail decision thresholds a Vehicle model can be determined to Pass, Fail, or require more vehicles to be tested.
Results 1 Vehicle model tested (Euro III Petrol Mitsubishi Carisma 1.8 GDi Automatic) was a continuation of testing carried out in previous years. This model had only one vehicle tested in the 2005/6 programme. When the test statistic was applied the result of this test combined with the previous years work appeared to give a FAIL decision on NOx Emissions. CO2 emissions for this vehicle also did not appear to conform to the type approval values. However subsequent investigations suggested that a number of the vehicles had not been serviced according to the manufacturer’s recommendations or had stored OBD fault codes (both reasons to reject the vehicles from the sample according to Directive 70/220/EEC procedures). When these vehicles are discarded from the sample the result becomes a ‘TEST MORE’ conclusion. 3 examples of the Euro III Diesel vehicle model (Mercedes A170 1.7l auto and manual) were tested. The model achieved a PASS decision for compliance of regulated pollutant emissions, but a decision of ‘TEST MORE’ was determined for CO2 compliance.

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