the saw chain cutters are the same part # for .050 .058 and .063 chain in same pitch, so fail to see why you would need more HP?Of course there is a difference from 050 to 063. My 2 cent not much. I have some bars that have hundreds of cords or thousand and are still going strong. Start with 050 gets worn then go to 058 then go to 063. I pretty much can not determine any difference. The difference is very small. If you like a 063 bar use it. It will take mega HP to pull a wider chain yes. That mega HP might be measured as a hundredth of a HP or not noticeable. Some have said the wider chain is more durable then use it. Thanks