Wingtip modifications will save Alaska Airlines $20 million annually

[NickB79]

9. Over 7700 737's have been built so far

Per Wikipedia:

The 737 series is the best-selling jet airliner in the history of aviation.[4] The 737 has been continuously manufactured by Boeing since 1967 with 7,755 aircraft delivered and 3,467 orders yet to be fulfilled as of September 2013.[1] 737 assembly is centered at the Boeing Renton Factory in Renton, Washington. Many 737s serve markets previously filled by 707, 727, 757, DC-9, and MD-80/MD-90 airliners, and the aircraft currently competes primarily with the Airbus A320 family.[6] There are, on average, 1,250 Boeing 737s airborne at any given time, with two departing or landing somewhere every five seconds.[7]

If we assume only 5,000 are currently still in service, at 58,000 gal. saved per year per aircraft, this modification done fleetwide would save 290 MILLION gallons per year!

Wow.