Tom Cruise enjoyed being the "top gun" on the Top Gear racetrack, he said.
In between promoting his latest film, Knight And Day, in the UK, the Mission: Impossible actor, 48, found time to race around the famous track against co-star Cameron Diaz.
"It was fun, very fun. I like fast cars and motorcycles - I've always loved them since I was a kid," he said on the red carpet at the film's premiere in London.
The two Hollywood stars were racing one another in a Kia cee'd in a bid to complete the fastest lap, and the results will be shown on Sunday's Top Gear show on BBC Two.
Cameron, who glittered in a silver sequinned Stella McCartney minidress, admitted she was finding it difficult to keep their scores a secret.
"We did timed laps. It's very exciting - we know the score and we want to tell everybody, but we can't because we want them to watch the show," she said.
The 37-year-old added: "I love speed. What I love about it is that you have to live in the moment, and I love just being in the moment."
The duo reunited for action comedy Knight And Day - their first film together since 2001's Vanilla Sky. Tom heaped praise on his co-star, saying: "Cameron is such a great actress to work with every day. She's someone who brings a smile every day, she's just someone who is very fun to be around."
The actress returned the compliment, saying: "Tom is just amazing and so much fun. We had a laugh every day, and did the best work we could."
The high-octane blockbuster, directed by James Mangold, will be released on Friday August 6.
© Press Association