Yes, the charts a guideline to keep you in the 8W range, if memory serves... But we all know that not all juices like 8W... some like 12W, some turn to charcoal at 5W... so that is why we say 'sweet-spot'... start low, and keep turning it up until you get a burnt flavor, and back it down a notch or two... What gets me is one of my ADV's is best at 14W +/- a Watt or two... and the other can't be pushed over 9W... so when I put the wrong tank on the wrong battery, I sometimes get a huge surprise (and a crudded-up coil)...