There are many factors that come into this like the type of soil, the gradient and so forth so trying to make some x hp / foot rule and sticking to it isn't always a good idea. You have a pretty powerful tractor and you should be using implements that match it correctly, otherwise you're just wasting diesel. I use a 5065e for mowing our horse pastures. I am using a flail mower that is just over 7 foot and it works perfectly fine (requires 50-55 HP according to specs). Bear in mind that a flail mower is a lot more heavy duty than a deck mower and requires more power. 100+ HP is plenty enough grunt for a decent sized topper, but what are you topping and what are the ground conditions like?Ah, ok, I was being honest when I asked about the 20-30' mower not sensitive. The dealer says 7' is lots and you guys say it's too small (I'll take your guys' word first any day cause experience takes over dealer knowledge on this stuff.)
So is it safe to say I should stick with 4hp/ft. for most attachments and 10hp/ft. for the heavy digging/ground engaging attachments? This is the type of info that's good to know cause I asked the dealer about harrows for the pasture and he said I could use any size I wanted, is that true? Cause (I would never use this big) that would mean I could pull a 50' or 70' harrow.
As for cultivators etc. I use a 10 foot spring tine cultivator and a 10 foot chain harrow (not a drag one) and could easily use a bigger one.