While other German manufacturers have been talking about fitting an engine stop-start system to cars with large engines and automatic transmission, Porsche has trumped them all with the Panamera.
From the start of sales, all three versions of the new V8-engined Porsche Panamera will have this fuel-saving device. Previously it has been seen only on four-cylinder cars from rival makers.
Even more significantly, it means that engine stop-start is being offered with an automatic gearbox for the first time, contributing towards fuel savings of up to 23%.
As the driver brakes to a standstill, sensors detect that the car is coming to rest and cut the engine. A hill-hold function does away with the need to apply the handbrake manually.
As soon as the driver starts to release the footbrake the engine kicks in again.
Porsche has even made it possible to disable the system for people who live in unusually hilly cities such as San Francisco, to avoid unnecessary wear on components.