Marco,
Read the specs on the Kubota '40 series tractors with the new HST. It is pretty dern close to perfect.
Mechanically, just about any transmission is reliable. The best place for improvement will come from power / load management with accurate predictive capability. As you power into a pile of dirt, you want maximum torque available so high rpm's and high torque multiplication are desired (Low Range). Variations in speed still done by the HST peddle. Backing away from the pile, less power is needed and higher speeds are desired. Rpm's drop and gear range would go up to medium-low. As you take the load to the new location the tractor would optimize the power and minimize the fuel use while matching your speed desired. Grear range may stay medium-low or go to medium or medium-high. When you slow to raise the FEL and dump the load, the tractor would drop to low gear range and up the rpms so you can quickly move the loader up and slowly / exactly positon the tractor. This will require more than the standard 2-3 ranges for the HST to operate in. Maybe 6 ranges or and IVT.
Dropping the empty bucket would trigger the tractor into a higher speed mode for the return trip with minimum power and maximum fuel economy.
All of this would be done seamlessly. The operator would only know that the tractor moves at the exact speed he wants it to and was at the exact rpm range to accomplish the desired task. Overall, this should result in longer service life of the equipment and 10-15% less fuel used. Sensors would tell the tractor what was needed. Such as wheel speed vs ground speed for each wheel (able to lock rear axle, front axle and go to 4wd as needed), Verticle vs horizontal load on the bucket, 3 axis accelerometers to determine jounce and adjust max speed, capacitance sensors on the controls to determine where operators hands are resting, etc.
Sorry if this is a bit disjointed, but it's pretty much off the cuff.
jb
