This spring I managed to buy a couple of cords of Douglas Fir in "rounds" so I have split it myself. Decent price ($130) a cord. I have been splitting it into average 6.5inch thickness, and the usual 15" length. Previously, I have gotten my wood split and del. And the average thickness was about 4.5 to 5 inches thick. Because I can`t burn my thicker splits until next winter, I don`t know how that is going to work out? I`m thinking that a longer burn time, and maybe even more heat? Which begs the question? What are most of you experienced burners using? Even bigger splits, smaller? And the results? I believe I can pickup another 2 cords of this nice stuff in March, and wouldn`t mind knowing in advance if I should be splitting this even larger,or what? I don`t need smaller pieces to get a rip-roaring fire going, also got 5 cords of cedar last year (mill ends) so lots of good kindling. @My insert is a 1985 PE with new baffle., SS liner right to the top of chimney. (5.5") good draft. 22ft. It looks like with the larger splits I can cram 4 in there at one time for a longer burn. Thanks Guys, and all the best for the season.!!