THAT is the article I was looking for, THANK YOU!!!!
In summary:
"A typical piston airplane’s maximum-range speed is about 10 percent above L/D max"
"Simply multiply your airplane’s best-glide speed by 1.316—or add 32 percent—and that’s the Carson number. "
This means for the Kitfox with its best glide speed of 65mph :
best range: 72mph ( 65*1.1)
Carson speed (best value): 85mph (65*1.316)
I now have the next two airspeeds to measure fuel economy!