The Effect of Fuel Sulphur Content on the Exhaust Emissions from a Lean Burn Gasoline Direct Injection Vehicle Marketed in Europe

The effect of fuel sulphur on emissions from a lean-burn G-DI passenger car homologated according to German D3 specifications was investigated over the European drive cycles. In addition some tests over US Federal cycles were conducted. No statistically significant deterioration in tailpipe emissions was detected with the leanburn G-DI technology using a selective reduction type de-NOx catalyst at fuel sulphur levels from 30 to 300 mg/kg. The emission response to fuel sulphur level was essentially flat, and the sulphur effect was less than that seen in the EPEFE fleet. Tests were conducted applying a rigorous test protocol including four repeats with each fuel and a desulphation procedure between fuel changes.

Approximately 15-20% improvement in fuel economy over comparable MPI cars was predicted based on the CO₂ results from the current programme and German type approval data. Increased particulate mass emissions were observed, compared with typical MPI cars.