That's what Boeing is marketing it as, but the 757 has higher performance. Being designed for turbojet engines, the 737 is too low to the ground to use any bigg

That's what Boeing is marketing it as, but the 757 has higher performance. Being designed for turbojet engines, the 737 is too low to the ground to use any bigger turbofan engines than it currently does, and getting it higher off the ground is difficult (can't just shove a taller landing gear in there). The -9 (if I remember correctly) will need a telescoping landing gear in order to fit big enough engines under the wings. The design seems pretty maxed out in that regard.