2-Cycle vs 4-Cycle Engines
2-cycle engines require a mixture of gas and oil in the fuel tank. Also known as 2-stroke engines, these are lighter and simpler to maintain than a 4-cycle engine.
2-cycle engines can also produce twice the power as a 4-cycle engine, giving them a greater power-to-weight ratio compared to 4-cycle engines. This makes a 2-cycle engine an ideal solution for powering a handheld leaf blower.
4- cycle engines work similarly to a vehicle engine. Gas goes in the fuel tank and oil goes in the crankcase. They are more fuel efficient than a 2-cycle engine, so you get more “mileage” out of every tank of gas, and you don't have to mess with mixing gas and oil.
A 4-cycle engine has the potential to produce more power than a 2-cycle engine, but will require an increase in the size of the engine. Larger engines may be undesirable, given the extra weight you'll be carrying.
Due to pollution issues in its state, the California Air Resource Board has enacted legislation which requires small engines meet emissions standards. Lawn tools such as leaf blowers fall under this regulation.
If you live in California, make sure you choose a CARB-compliant leaf blower. While older blowers had developed a bad reputation for their emissions, CARB-compliant models are more efficient and run cleaner. They will, however, still emit some pollutants.