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To investigate the effect of removing phosphorus lubricant additives from engine oil, a mileage accumulation programme was run using four 1.6 litre gasoline vehicles, two of which used phosphorus based lubricant oil additives, and the other two used boron based lubricant oil additives. The work showed that the catalyst systems deactivate during mileage accumulation, but emissions were still within the European Stage IV legislative limits at the completion of the mileage accumulation programme. Vehicles run with the boron oil show lower tailpipe emissions than the vehicles run with the phosphorus oil.

This paper describes the development of new high performance three-way catalyst (TWC) formulations with improved activity and enhanced thermal stability. These new TWC formulations enable the converter to be fitted closer to the engine and allow this future legislation to be met with catalysts using PGM levels significantly lower than those currently being employed. The performance benefits of these advanced platinum- and palladium-based catalysts are demonstrated on a number of different vehicles after bench-engine ageing.

Catalysed hydrocarbon traps (CHT) have been tested in conjunction with the Exhaust Gas Ignition (EGI) system to assess their combined impact on cold start total hydrocarbon (THC) emissions reduction. Vehicle emissions profiles have been obtained for each of the regulated emissions along with speciated HC exhaust gases for each of the different CHT-EGI combinations studied in the program. Results show that the combination of EGI and an upstream CHT lead to a reduction in THC emissions of 30% during the 1st 195 sec of the New European Drive Cycle. In addition, the EGI system alone, and in conjunction with a CHT comfortably achieves the proposed European Stage IV legislation for each of the regulated emissions at 50k miles. The significance of the results are discussed with reference to both standard drive cycles and off-cycle emissions.