Porsche will reveal a hybrid version of its Panamera high-performance luxury car at the Geneva motor show next month.
Despite its combined 375bhp, 0-62mph time of 6.0 seconds and top speed of 168mph, the Hybrid S has emissions of just 159g/km and an average economy figure of 30.4mpg.
Porsche boasts that the Panamera has the best bhp/CO2 ratio of any car on the road.
Nudging below the 160g/km mark also means fleets can offset the price of the Panamera Hybrid S against tax at 20% per year.
The car has a 329bhp 3.0-litre supercharged V6 and a 46bhp electric motor. The nickel metal hydride battery can power the car on electricity alone for around 1.25 miles at speeds of up to 53mph.
It goes on sale in June, from 86,147.