The larger the saw, the more likely it's intended for big slab work or to decrease the time it takes to cut the slab. Diesel power walk behind saws become available as saws go up in size. Diesel engines have more torque than gas and the liquid-cooled engine delivers a smoother running, longer lasting saw with higher productivity. Diesel self-propelled saws are easier to maneuver, important when using larger walk behind equipment. Diesel has one of the higher up-front costs but at the same time have more efficient engines, reducing hourly costs to complete a job.