simple question,, throttle or drives

Is it better to control a ztr mower speed with the throttle or with the drives?

Please refrain form posting the same question in different sections of the forum.
Same answer as before
The engine should always be run at full throttle.
This is best for both the engine and the hydro pump.
Fastest way to kill a hydro is to run the engine at a slow speed and the hydro flat out