F1's global television audience is in decline, according to FIA president Jean Todt.
The Frenchman told German magazine Auto Motor und Sport that he thinks the problem is the questionable spectacle of some grands prix.
"Races like Abu Dhabi in 2010, where you cannot overtake, are unacceptable," said Todt, who appears increasingly at odds with F1's chief executive Bernie Ecclestone.
He said "Recent data indicates a fall in the numbers of spectators. People have many choices in how to spend their leisure and every day we must ask ourselves how we can improve the entertainment".
Todt repeated his recent claim that one striking problem is the visibility of the drivers.
"On television I can hardly tell who is at the wheel of each car," he said. "Only the experts know the helmets and many drivers change their design race to race.
"NASCAR does a good job. A driver, getting a starting number that he keeps for all his career, is immediately identifiable by the fans."
On television I can hardly tell who is at the wheel of each car
Todt also defended F1's new 'green' engine rules for 2013.
"One day governments will prohibit certain types of cars or engines. The FIA needs to demonstrate it is moving forward, even if it brings us no new fans," he said.
"The bigger you are, the greater the role model you have to be."