The next major Tesla software update will give all versions of the electric car "full self-driving features," chief executve Elon Musk has announced.

In response to comments on Twitter from Tesla owners about suggested features, Mr Musk said the update would fix issues with the system understanding lane merging and go even further.

"That issue is better in latest autopilot software rolling out now and fully fixed in August update as part of our long-awaited Tesla Version Nine," Mr Musk said.

"To date, autopilot resources have rightly focused entirely on safety. With V9, we will begin to enable full self-driving features."

All Tesla vehicles are already equipped with the hardware to give them full self-driving capabilities, such as cameras and sensors, however the current software means they are only semi-autonomous.

According to the electric car maker's website, full self-driving capability delivers a safety level "substantially greater" than that of a human driver.

"The system is designed to be able to conduct short and long distance trips with no action required by the person in the driver's seat," Tesla's website states.

"All you will need to do is get in and tell your car where to go. If you don't say anything, the car will look at your calendar and take you there as the assumed destination or just home if nothing is on the calendar."

Subsequent tweets from the Tesla CEO suggested the new Tesla Roadster – the company's most expensive electric car – would feature an improved top speed that would make it outperform gas vehicles "on every performance metric".

The billionaire claimed the Roadster would become the world's quickest production car, capable of going from 0 to 60 mph in 1.9 seconds.

Mr Musk has previously criticised media coverage of his company, which he says unfairly reports accidents involving Tesla vehicles disproportionately more than accidents involving vehicles not equipped with self-driving capabilities.

There have been a number of accidents in recent months involving Tesla cars, including a fatal collision in California in March.

"It's super messed up that a Tesla crash resulting in a broken ankle is front page news and the 40,000 people who died in US auto accidents alone in the past year get almost no coverage," Mr Musk said on Twitter last month, in response to an article in The Washington Post.

"What's actually amazing about this accident is that a Model S hit a fire truck at 60mph and the driver only broke an ankle. An impact at that speed usually results in severe injury or death."