Engine Warm-up Procedures
 

I would be interested on views cocerning engine warm-up procedures to enhance engine efficiency and increase EGT margins. Presently my company starts engines and within 10-15 minutes are setting either T/O rated thrust or Reduced thrust for departure. Engine monitoring is giving reduced EGT margins and the company is looking for ways to increase them by developing warm-up procedures. The engine manufacturer are not very helpful. Without giving to much away the engines are old PWs. Views most welcome.