Brush Truck
A smaller, higher-clearance apparatus built to fight vegetation fire away from roads. Usually four-wheel drive with a modest pump and tank.
A brush truck is built for ground a full-size engine cannot reach: unpaved, steep or narrow terrain, fighting vegetation fire. It trades water capacity and pump size for clearance, maneuverability and off-road capability.
Its maintenance profile has more in common with off-road equipment than with a street apparatus. It works in dirt, brush and heat, often off pavement, so undercarriage damage, cooling, tires and driveline wear dominate, and hours matter more than miles.
The other planning point is seasonality. A brush fleet is worked hard in a season and parked outside it, which is exactly the pattern a naive utilization report reads as underuse. It is standby capacity, and the report should be told so.