A wheel loader today is comprised of a pivoted frame, usually articulated, with the engine mounted over the rear wheels, and a cab or canopy resting over the front or rear end frame. The pivot arrangement of the machine is key in giving the wheel loader the capability to maneuver and work in small turning circles.
Wheel loaders are segmented in the market according to their horsepower. Compact wheel loaders are loaders with 80 horsepower or less, and then the classification is broken down accordingly from 80 to 150 horsepower, 150 to 200 horsepower and 200 to 250 horsepower.
Power is supplied from a diesel engine through a torque converter and power shift gears to drive the wheels. Most wheel loaders are now four-wheel drive requiring that all wheels be of the same size but the machines can be operated in two-wheel drive too. Rear wheel drive enhances the machine's digging capability while front wheel drive enables better traction when carrying a full bucket.
In the equipment industry a set of specification criteria are used to measure a wheel loader's performance capacity and usefulness for handling certain construction applications. These include bucket features including the size of the bucket and cutting edges or teeth, tires and their ability to provide traction, tipping load and counterweight, speed, and breakout force. Breakout force is the most-quoted specification for wheel loaders and provides an indication of a wheel loader's digging ability.