What are you using to crunch those numbers?
Also, we've been using a ton of sparge water. I'd say we mashed with something close to your suggested 8.26, but we must have sparged with 20 gallons of water. If we were to use 4 or 5 gallons sparge we would end up with a very low gravity. As I was saying earlier we probably fill the pot up with 18 gallons then boil down to 9 or 10 to achieve our still-low gravities. (it must take an hour or two boil time to cut it down, not including the hour for hops)
Let me also mention, when we sparge, we continuously run sparge water until the wort coming out is below 1.008. So, when we finally call it enough and close the valve on the mash tun, it still has many gallons of water in it that didn't get through. Is it in any way better to let the mash compact as you get to the end of your runoff?