Pushing Innovation in Fuel Efficiency
Fuel efficiency initiatives are directly linked to our ability to offer low-cost air travel. We have invested more than $565 million in fuel efficiency improvements since 2002, including adding winglets to our aircraft, engine upgrades, engine washes, use of ground power at airport gates, and controlled ground idle speeds. For example, all of our Boeing 737-800 aircraft have split-scimitar winglets installed to reduce air resistance, resulting in additional savings of 1.28 million gallons of fuel and 12,554 metric tons of CO2e in 2016 compared with 2015.
We continued our fleet modernization program in 2016, retiring 42 of our older aircraft, including 737-300 aircraft and all of our remaining 737-500 aircraft. We took delivery of 38 new 737-800s, which now comprise 20 percent of our total fleet. These airplanes offer significant fuel savings on an available seat mile3 basis compared with our Boeing 737-300 aircraft, which are scheduled to be completely retired by the end of third quarter 2017.1 The Boeing 737 MAX 8 is expected to provide over 20 percent greater fuel efficiency compared with the 737-300 aircraft on a gallons per available seat mile basis.