Will different coal burn more efficiently?

Hi all, Into my third ton of coal in my first season with a coal feeder stove. I changed coal for this third ton. I had to change my feed rate max from the 35 area to about 26 to make sure unburnt coal wasn't falling off the grate. Is it typical that different coal will effect the amount of coal that I see burning along the grate? Thanks!

yes,
every coal brand is slightly different, and even the same brand with different load will burn slightly different.
As your finding out you may need to do some adjusting for max efficienty and welcome

Yep - what Dennis said. You can have the exact same brand a year later and it'll be totally different. Can change during the season too. With coal, nothing is set in stone as far as quality goes. Hit or miss, although some brands are MUCH better than others.

Yup! What Dennis and Smitty said!

Yes, yep, yup--what Dennis, SMITTY & Allen all said