[NJA_Capt]

Originally Posted by ScottG

.....basically what are the general indications for maximum possible ground speed.

From a layman's point of view, go to the AFM and find the altitude that provides the highest true airspeed for the given weight/temp. For the Citation X, the highest TAS is between FL370-FL410.

http://citationx.cessna.com/performance.chtml