I used 1000rpm for tedding hay. Often when hay turns into dry hay, the PZ Fanex 500 didnt have enough speed for the light material so it would create windrows. 1000rpm PTO at 1200 engine rpm did the trick. But for heavy implements you need to check the engine temperature at hot summer days, as the fan also turns slower. Some tractors have been toasted driving a stationary irrigation pump at 1200 engine rpm in hot summer weather.