In December 2010, Airbus announced new fuel-saving engines for the single-aisle A319, A320 and A321 jetliners. Dubbed NEO, for new engine option, the programme also introduced new wingtip devices – the upturned ends of the wings – called Sharklets that reduce drag-inducing vortices.
Together, the changes resulted in a 15 percent reduction in fuel consumption, two tonnes of additional payload capacity, up to 500 more nautical miles of range, lower operating costs, and reductions in engine noise and emissions – all while retaining 95 percent commonality with the A320ceo (current engine option) aircraft.
Four years later, Airbus brought the NEO concept to the A330, also offering reduced fuel consumption and improved range.
Source : Airbus Website