Gas-powered tillers rotate soil, allowing nutrients, water, and air to distribute more evenly throughout the soil. These devices also help keep soil from compacting, which can discourage many plants from taking root. Regularly tilling a garden helps promote healthy and vigorous plant growth. Rear-tine tillers and front-tine tillers are the two most widely used types of tillers for farming and recreational gardening applications.
Gas tillers are available with two- or four-stroke engines. Four-stroke engine gas tiller models run cleaner and produce less emissions than two-stroke engine models do. A two-stroke engine model may run on a fuel combination of gasoline and oil while a four-stroke engine is designed for use with gasoline only as fuel.
The tines on a front-tine gas tiller are located under the engine, in front of the tiller's wheels. The term “mini cultivators" is often used to refer to a smaller model front-tine tiller. These are ideal for working on smaller yards or areas that feature softer soil. Gardens with less than 1,000 square feet (93 square meters) of space may only call for a mini cultivator, depending on the hardness of the soil in the garden.
Rear-tine gas tillers are among the most efficient tillers available. Unlike in front-tine gas tiller construction, a rear-tine tiller's digging tines are situated behind its wheels. These tillers will feature either standard or counter-rotating tines. They offer strong digging power and are ideal for tilling larger areas or areas with harder soil.
Typical tilling widths on most gas tillers can range anywhere between eight inches (20.3 centimeters) and 24 inches (61 centimeters). For more efficient tilling, several manufacturers make gas tillers that can reverse digging direction. Tillers typically feature adjustment systems to allow for tilling at various levels.
Compared with electric tillers, gas tillers offer higher horsepower output. Gas-powered models are also more portable than electric models; electric tillers may require extension cords and can only operate near a power source. Gas tillers however, are noisy and require more regular maintenance than electric tillers.
Tillers not only rotate soil, they bring buried rocks up to the surface where they are more easily accessible for removal. Several manufacturers make gas tillers that can be fitted with different attachments, such as lawn dethatchers and aerators. Lawn dethachers are designed to remove yellowing or dead grass and weeds. Aerators cut into soil and promote deeper oxygen, water, and nutrient penetration into the soil.