Why Did Boeing Build The 787 With 2 Different Engine Types?

Why would Boeing offer two completely different engines on the same airplane? The decision to power the Dreamliner with either the General Electric GEnx-1B or the Rolls-Royce Trent 1000 remains one of the program’s defining strategic moves. It matters because engine choice directly influences fuel burn, dispatch reliability, maintenance cycles, noise footprint, ETOPS (Extended-range Twin-engine Operational Performance Standards) clearance, and fleet commonality. It can also shape an airline’s profitability.