NEW YORK — The only goal The Rolling Stones have left in their career is to rock on till the wheels fall off.

“The only goal left is to see how far we can run the string,” Keith Richards, 71, said, laughing. “The band feels great about playing. I mean, you couldn’t get these guys to do anything if they didn’t wanna. It’s what we do, so we’re just hoping for a great summer.”

The Stones — who’ve played together for more than 50 years — will kick off a 15-city stadium tour of North America on May 24 at Petco Park in San Diego, California.

Mick Jagger said the advice he would give other bands who want to play as long as the Stones is to make every show count.

“Every night the audience is like a challenge for me. Every time you go out there it’s different. You think it’s the same show, but it’s a different show, different place, different audience,” said Jagger, 71. “For a younger band, you got to bring a sense of uniqueness to every show you do and you got to sort of try somehow to forgot — even though it appears to everyone it’s the same show — but to yourself it’s always got something different and special about it.”

Life on the road isn’t for everyone, Jagger said: “I’m not sure if all young bands want to stay on the road as long as we have,” he said with a laugh. “Maybe they’ll want to do something else.”