U2 are "at the absolute limit" with their 360 Degree tour, and are "as big" as they could "ever get".
The 'Vertigo' rockers were declared to have the highest grossing tour ever - beating a record set by The Rolling Stones - last week, having made £341million pounds with 20 dates to go, but the tour itself is also the most expensive ever staged, taking 120 lorries to transport its 50-metre tall sound system, stage and lighting rig.
Guitarist The Edge told Rolling Stone magazine: "We're actually at the limit, the absolute limit, when you consider the economics and the practicality of transportation. We're really as big as we could ever get."
Bass player Adam Clayton added: "Somebody asked us last night, 'Do you need this stuff?' And the truth is, you don't really need this stuff.
"But part of show business is you have to change people's perceptions, you have to find ways to make the songs touch people more, to disorientate people so they're more open to being touched."
By the time the 360 degree tour ends after two years on the road in July, the band - which also includes singer Bono and drummer Larry Mullen - will have played to more than three million fans in over 20 countries around the world, however, despite travelling the globe, the group don't actually get to see much of the countries they visit.
Speaking before a recent show in Croatia, The Edge said: "This will be my Zagreb experience. It's the one thing that's strange about touring - you don't get to see things."