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Anyone know the glide ratio for my 63 M20D. I need to input that into my Stratus 2. Can not find it in the POH. Thank You!

The weather turned nice here today with clearing skies, calm winds, and warm temps. So I went flying. Don't tell my wife. Okay, go ahead; she already knows. As I like to try new things and learn more about my baby (27 months mine) today's flight was to see first-hand how far I could glide in a power out situation. And boy was I surprised! I've always been told and used 10-1 for a glide ratio calculation so anytime I'm cruising I figure I can glide about 1.6 nm for every 1,000' AGL in calm air. Looking at my POH it's a bit more optimistic showing a glide ratio of over 11-1. But in today's test flight I beat that easily, achieving a glide ratio of 13.8 - 1. Needless to say I was gleefully surprised! I set this up by departing my home base to the south climbing to 10,000 AGL about 20nm from the airport. I turned east and reduced power to slowly stabilize the temps as low as possible (to minimize the possibility of shock cooling) before turning back north towards the airport. When I was 16nm from the airport (GPS distance) I pulled the power to idle and the prop control all the way back keeping the airframe in a clean configuration. I then trimmed for an airspeed of ~100ias and started the glide. It was weird seeing the prop turning so slowly (<1,000 rpm) and the engine was making virtually no power. I couldn't hear the engine running and before too long the EGTs on my JPI830 went completely off-scale (low). I occasionally advanced the throttle just a bit to make sure it would power up, but for only a half-second or so (not long enough to affect the results I believe). As I approached the airport I couldn't believe how HIGH I still was; I had expected to be set up for an approach after starting 16nm out at 10,000AGL. Instead I decided to go ahead and milk the glide as far as I could (down to 1,000AGL). When I crossed the threshold my altitude was still 2,900AGL! So, I continued to the 0nm point at the airport's center before turning west. From that point I glided another 4.5nm before finally dropping down to 1,000AGL at which point I eased in some throttle and prop to arrest the descent. I babied it back in to the runway on a long base-to-final to avoid heating it back up too quickly after the long descent at no power. I had glided 20.5nm or approximately 124,500' while only giving up 9,000' of altitude! This is much better performance than I expected. I will qualify by stating that I was at a weight of 2,300#; not gross. But I also was a bit faster than the book speed for best glide which is stated as 98ias (105ias @ 2,740#). I don't know how much another 440# would affect the glide but my POH only has the one graph for this calculation and it doesn't state which weight is shown. I suspect it's for gross. In any case, from now on while cruising I won't necessarily rule out those airports 20nm-22nm away while in the 10,000AGL range. In fact, for most of my flights I believe that a glide ratio of 13-1 is fairly conservative based on today's test flight. Any comments, questions, suggestions? I'd love to know if anybody else has done this and what their results were. CNOE