10 Gallon Batches, efficiency went up?

I did my first 10 gallons batches yesterday (double brew day). Batch sparging. Both beers were similar estimated gravities. 1051 & 1046. My final volumes came out only slightly higher, but not bad as far as I’m concerned.

I have been consistently getting 71% efficiency for a while now. I got 78% and 79% yesterday. I’m really not complaining about higher efficiency, but I would like to know why, and would like to be consistent.

The only thing that was different yesterday was my mash temps held pretty constant. Only losing a degree or so. I’ve had problems in the past with losing as much as 5 degrees. The added volume and less head space in the mash tun really helped.

I also noted that my first running volumes were higher than expected, so I had to reduce my sparge water to get my desired boil volume. I used the same absorption ratio I always do and same crush.

Can anyone give me any insight into my higher efficiency? From what I read, I thought I may actually get lower.

Cheers!

Temperature should definately have something to do with it. I only ever do 47l batches when I do all grain, and they hold their energy much more than they did at a smaller volume.

Also, have you changed equipment at all since you switched to 10 gal batches? The dead space at the bottom of my tun is the same regardless of batchsize, so I assume it is more efficient when I fill it to capacity.

Equipment is the same as before. I didn’t change anything but the size of the batch. They are recipes I’ve done before, just scaled up.