The 7 Best Zero-Turn Lawn Mowers Make Short Work of Big Grass-Cutting Jobs. ... The Kawasaki gas engine in this ZTR has 21.5 horsepower, which should be than enough for a 42-inch mower.

Our top choice is the Ryobi 42-Inch Electric Cordless Zero-Turn Mower, which cuts grass for up to 3 acres on a single charge and is packed with design elements to keep you comfortable as you work.