HST is short for hydrostatic transmission. It is roughly the same as an automatic transmission on a car. That may be a bit of a simplistic comparison but it is fairly valid never the less. On a HST pedal, the harder you press on the pedal the faster the tractor goes so that is why the comparison is valid when comparing it to a car's automatic transmission. However, as the pressure on the pedal is increase the amount of torque available to the wheels is simultaneously decreased. This is an important difference to keep in mind. As you are trying to dig into a dirt pile if you press harder on the HST pedal, you are actually reducing the amount of power to the wheels. It is a bit convoluted, but to increase the torque you can reduce pressure to the HST pedal and the torque will increase. As for shifting, you do have a range selector with HST, you pick a range (typically LOW & HIGH or LOW, MID & HIGH) and then you simply press the pedal.
All that said, HST is simple to use right from the start. It is very efficient for most uses. It is very user friendly. It increases resale value in the tractor should you sell it. It is very reliable, typical lifespans before some sort of a rebuild reportedly run about every 5000 hours.
I was writing while DocHeb was writing and he posted first, so I came back to edit in some stuff and let me say I am not a girly-man but I am a proponent of HST. I tend to think that when something scary jumps out in front of me I scream like a little girl and run the other way. But hey, I didn't grow up in the country with tractors, I grew up as a city & suburban boy who moved out to country and I started playing with tractors. I don't pretend to be a "real" farmer, but I've used real farm tractors and I've used CUTs and I've used both HST and GEAR. I simply prefer HST and find it easy and efficient. Would I use HST if I were plowing fields. NO. But for use on a gentleman's farm or small estate type property then HST is, in my opinion, a great choice.
