Engine lifespan

1. Zero-Turn Mower: Air-Cooled Vs. Liquid-Cooled (Clarified)
2. Zero-Turn Mower: 2-Stroke Vs. 4-Stroke Engines (Unpacked)
3. Zero-Turn: Carburetor Vs. Fuel Injection (Defined)
4. Zero-Turn: Residential Vs. Semi-Pro Models (Defined)