Just looking at an engine’s horsepower isn’t enough.
You have to see how much power is delivered to the ground.

The Apache PTG Technology Delivers 90% of the Engine’s Horsepower to the Ground
Most Hydrostatic Sprayers Deliver About 70% of the Engine’s Horsepower to the Ground

With a hydrostat, PTG is complex and inefficient:

    1. Engine
    2. Hydraulic pump (about 2% hp loss occurs here)
    3. – 8. Hydraulic block, plus each hydraulic union and fitting is a point where hydraulic pressure can be lost. Loss of pressure means loss of power (about 8% hp loss occurs here)
    4. Hydraulic wheel motors (about 5% hp loss at each wheel motor)

So hydrostatic sprayers need more horsepower to:

Lug around 3,000 to 9,500 pounds extra weight, including four hydrostatic wheel motors and pumps.
Compensate for their wasted power; 25-40% of the horsepower is lost before it even hits the ground.

Competitor Undercarriage Photo View Apache Undercarriage