Your higher altitude extended your range. I assume you used bottled O2 - becaue a flight that long at 13K would definitely impair your mental capacity. Also, leaning the engine down that much helps extend the range, but would likely cut a little time off your TBO.
The Cessna web site list the Current C-172 model range is 640 nm - with a 45 minute reserve @ 12,000 ft @ 45% power and a payload of no more than about 550 lbs.
Ranges are listed rather conservative by the manufacturers, and always include an efficient cruise speed, altitude and a reserve. It is normal in the real world for efficient, conservative pilots to be able to get quite a lot more range out of a new aircraft than the listed number. And to get quite a bit less range out of older aircraft where the engine is not as efficient.
I assume you are refering to natical miles and not statue miles with your numbers since GCM puts the distance between those airports at 701 nm.
Last edited by ReggieF5421; 06-17-2012 at 05:04 PM.
@ PawPaw's house - near KADS, Addison, Texas, USA