What Are Self-Propelled Lawn Mowers?

Front or Rear Drive

• Self-propelled mowers use two basic options for the engine to drive wheels as well as turn the cutting blade. One is front-wheel drive, with the two front wheels driven by the motor to pull the mower forward. The other is rear-wheel drive, with the back wheels providing the propulsion. Both styles use either gears or belts to turn the wheels, the technique depending on the manufacturer.

Front Maneuverability, Rear Power

• Front-wheel drive is easier to maneuver. Putting pressure on the mower handle will lift the wheels slightly so that turning the mower is easier when going around trees or other obstacles or when changing the direction of the mowing path. Rear-wheel drive offers more traction and thus more force, which is especially useful if lawns have a lot of hills or slopes to mow or for cutting heavy grass.

Types of Discharge

• Three techniques are used in self-propelled lawn mowers to discharge grass clippings: side bag, rear bag or mulch. Side-bag mowers throw clippings out a chute on one side of the mower into a bag. Rear-baggers discharge clippings through a large opening in the back of the mower deck into a big bag. Mulching mowers grind clippings into small fragments and deposit them on the ground under the mower. Rear bags usually are larger and hold more grass; side bags tend to drag on the ground as they fill. Some mowers have options for either bagging or mulching.

Bigger Engines

• Usually with larger engines than conventional rotary mowers, self-propelled mowers generally have at least 6.5 horsepower (hp) versus 4.5 or 5 hp. The larger engines are needed to provide the extra power to both turn the blade and drive the wheels. Many self-propelled rear-wheel drive mowers have larger rear wheels for even more driving force.

Varying Speeds

• Offering varying speeds, many self-propelled mowers can be adjusted to the tempo of the user. All self-propelled mowers use safety releases -- bars on the mower handle which must be depressed to activate the mower and which stop it if released to prevent injury. Many self-propelled mowers have additional features like electric starters rather than pull ropes.