This beast is called GE9X — the largest jet engine ever built. Standing at 13 feet in diameter, it’s wider than a Boeing 737’s fuselage.

The GE9X on a test bed in Ohio. Credit: GE Aviation

General Electric designed the engine for Boeing‘s 777X airliner expected to roll out in 2020. Though it produces less power than its predecessor, the GE90-115B, the new GE9X is far more efficient — about 10 percent more. Not impressed? Well, in this field even a one percent bump is considered monumental. Just think of how much fuel this saves, turn that into dollars and multiply it by thousands of flights performed by hundreds of airliners over their life cycle. No need to do the math — it adds up to billions, trust me.

“The GE90 helped enable Boeing’s 777-300ER to have a dominant international route market position for the past 15 years,” says Richard Aboulafia, an aviation analyst with the Teal Group. The GE9X will allow “the 777-X series to maintain that market dominance for another few decades. It will likely be the largest, most powerful, and most advanced large turbofan built for some time.”