The 11% grade is an interesting variable. I used to live at 8,200’ and commuted to the Denver foothills every day. On the way to work, I went for miles without touching the gas while the instant mpg read 99 mpg. On the way home I’d get single digits going up the hill. I always thought that the two way average ended up being better that I could get on flat land.Hell I average almost 23 and usually pull a small trailer, up & down 11% grade every time I leave the house. I am just over 10K.