Elon Musk says it takes "100-hour weeks" to run Tesla.
The 47-year-old billionaire CEO of the electric car company has admitted it has become increasingly "difficult" to maintain production with the pressure of having to manufacture 5,000 Model 3 cars per week.
He told told the Recode podcast: "There were times when, some weeks ... I don't know. I haven't counted exactly, but I would just sort of sleep for a few hours, work, sleep for a few hours, work, seven days a week.
"It is incredibly difficult to survive as a car company. Incredibly difficult. People have no idea how much pain people at Tesla went through, including myself. It was excruciating."
Another added pressure he says, is the fact Tesla is the only brand delivering vehicles that have a "fundamental" impact on the environment, admitting that if the company "died" the world would be "dammed".
He said: "Tesla cannot die. Tesla is incredibly important for the future of sustainable transport and energy generation.
The fundamental purpose, the fundamental good that "Tesla provides is accelerating the advent of sustainable transport and energy production.
"This supersedes political parties, race, creed, religion, it doesn't matter. If we do not solve the environment, we're all damned."