Rush: Lauda Shocked By F1 Movie Crash Scenes

F1 legend Niki Lauda had no idea what happened in the crash that left him with horrific facial burns - until he saw the hospital scenes in a new movie depicting his infamous rivalry with James Hunt.

The Austrian returned to racing just weeks after his Ferrari left the track in the 1976 German Grand Prix as he tried to stop Hunt from being crowned champion.

Speaking at the world premiere of Rush, Lauda, who was trapped in his burning car for over a minute, told Sky News: "I was inside so I was busy staying alive.

"The movie is done very realistically and I, too, was shocked when I saw the hospital scenes, how they treated me, what they had to do to keep me alive.

"So even the movie for me was a shock in one way."

Ron Howard's new movie tells the story of the Hunt-Lauda rivalry - widely considered to be one of the fiercest sport has ever known.

"It's a gauntlet, emotional and physical, that they put themselves through to try to achieve greatness, to fulfil that need that they had (to win)," said Howard.

"All of that was only intensified by the fact that it was played out in Formula One - a world that is dangerous, that is visual, that is cinematic, that is so visceral - so I thought it was a fantastic combination."

Rush stars Australian actor Chris Hemsworth as playboy British racer Hunt - a risk-taker, with a penchant for drugs, women and alcohol.

Germany's Daniel Bruhl plays the dour, detail-obsessed Lauda.

Asked how he feels about his rival now, Lauda said: "I wish James could be here tonight, because this would be my best day.

"I feel very warm about him."

Hunt died from a heart attack in 1993, aged just 45.

His son Tom, who was also on the red carpet, said he was happy with his father's portrayal in the film.

He told Sky News he understood why Howard had covered his father's playboy lifestyle.

"There were bits of that involved in dad's life. That's part of who dad was - that's partly why he was so famous and popular."

Rush is released in the UK on September 13.