From my experience that glide ratio may be a little optimistic since the engine is running and probably putting out some thrust. When you shut down the engine and stop the prop it may not be as good. I did an engine and prop stopped on my 12 at best glide speed of 60 knots and got 10.3:1, less than the generally recognized ratio of 13:1. The 12 wing airfoil should be more efficient in glide than the 7.
Since I just finished a 7A I am interested in any real numbers. Reviews of others POH charts shows glide ranges of about 1 nm per 1000' for a ratio of 6.4-7.2:1 depending upon the prop position.
Scott- 2019 dues paid
New RV-7A N579RV first flight 6/26/2019, now in phase I
RV-12 N319RV 1st flight 12/2015, 310 hours probably on display for sale at Oshkosh
Purchased RV-12 sold, RV-9A- 536 hours sold, RV-7 sold, Kitfox sold