A man suffering from a pulmonary embolism in America was driven to hospital by his Tesla, potentially saving his life.

Lawyer Joshua Neally, 37, had joined the highway on his way home from work in Missouri when he suffered “the most excruciating pain I've ever had”.

He put the top-of-the-range Model X into Autopilot mode and instructed it to drive to a nearby hospital.

The car travelled 20 miles to the road where the hospital is situated and Neally steered it into the car park and checked himself into the A&E department.

Doctors said the embolism, a blockage of an artery in his lungs, could have been fatal.

"It was kinda getting scary. I called my wife and just said 'something’s wrong' and I couldn't breathe. I was gasping, kind of hyperventilating," Neally told local news station KY3.

"I just knew I had to get there, to the ER.”

Should he have passed out, the Tesla would have parked safely by the side of the road after a few minutes.

"I'm very thankful I had it, for this experience," he added, saying he believes Tesla vehicles will save more lives.

“If something like that happens where I become unconscious or incapacitated while I'm driving, I'm not going to cross over the interstate and slam into somebody or slam into one of the big rock walls.

"It's not going to be perfect, there's no technology that’s perfect, but I think the measure is that it's better and safer."

The electric car manufacturer's use of auto-steering technology is being investigated by the US road safety watchdog after a Tesla owner died in Florida when the driver-assist function failed to detect a truck in its path.

Tesla has always maintained that drivers using the Autopilot function should be immediately ready to take over in the event of an emergency.

Another of its electric cars was involved in a crash recently with the Autopilot function enabled.

Tesla CEO Elon Musk announced recently that he wants Tesla owners to be able to add their electric cars to a fleet of autonomous ‘taxis’.