The 17-vl has been struggling on 1 year seasoned oak. It's my first year burning so I don't have my supply where it needs to be. I Stumbled across some 2 year old beech and wow what a difference! I know it's a softer hardwood but this stuff throws some good heat! I can easily run in the 500° range. Can't wait until my oak gets to 20% but for now this will work!