Automakers and legislators in Europe are tightening the screws on CO2 emissions, and Porsche may turn to hybrid powertrains for the Cayenne and Panamera to meet a proposed 130 gram per kilometer limit. Bosch and Audi are reported partners in the effort to bring a gasoline/electric system to the Cayenne before 2010, with the Panamera falling in line, as well. While hybrid technology is typically used to boost fuel economy, the V8 and large vehicle size of the Porsche models are anathema to the studied aero shape of the Insight or Prius, and we doubt that Porsche has misgivings about the unbelievably strong torque delivery of an electric motor. You'll still be able to rocket around in your Wessiach thumper, but Porsche has got its eye on that 130g/kg CO2 target. If it becomes mandatory, the hybrid powertrain is a good hedge at being ready. In the meantime, Porsche is promoting a percentage reduction in CO2, rather than a blanket number for all vehicles.