Musk was very intentional about promoting Tesla’s autopilot as equivalent of self-driving L4 (if I remember right), even getting into fights with people who questioned the validity of the claim.
"U.S. electric vehicle maker Tesla is “very close” to achieving level 5 autonomous driving technology, CEO Elon Musk said on Thursday, referring to the capability to navigate roads without any driver input.
“I’m extremely confident that level 5, or essentially complete autonomy, will happen, and I think will happen very quickly,” Musk said in remarks made via a video message at the opening of Shanghai’s annual World Artificial Intelligence Conference (WAIC).
“I remain confident that we will have the basic functionality for level 5 autonomy complete this year.”
Obviously not exactly the same as making a definite statement about the capacity of current cars, but we all know what part of the message sticks with the public.
https://venturebeat.com/2020/07/09/elon-musk-says-tesla-is-v...
In the context of a software feature, "autopilot" implies a computer control system which is capable of maintaining rudimentary ongoing control of the vehicle.
Whereas a co-pilot is a whole other pilot. Surely that's worse, implying equivalence to a human sitting next to you, with comparable levels of training and skill, intuitively capable of taking over at any time. I wonder what would happen if Ford developed a system and called it "Co-pilot". We might never know.
Literally the opening paragraph of Wikipedia:
”An autopilot is a system used to control the trajectory of an aircraft, marine craft or spacecraft without requiring constant manual control by a human operator. Autopilots do not replace human operators. Instead, the autopilot assists the operator's control of the vehicle, allowing the operator to focus on broader aspects of operations (for example, monitoring the trajectory, weather and on-board systems).”