Posted by John McHaleSEATTLE, 23 July 2011. The first Next-Generation 737 aircraft from Boeing (NYSE: BA) with the new certified performance improvement engines was turned over to China Southern Airlines.The new CFM56-7BE engine system -- now standard on all delivered 737s -- has an improved design, which includes high and low pressure turbine modification. Combined with drag reduction enhancements that Boeing started designing into 737 production processes earlier this year, it will provide savings in fuel consumption and maintenance.The new engine is part of a 737 performance improvement package Boeing officials that Boeing began testing in late last year. Other fuel performance modifications will take place through next year.