The dial on this 3,000 psi-max washer controls the engine's rpm – the higher the rpm, the higher the psi (pounds of water pressure per square inch). Crank the dial to strip paint off masonry, or ease it down to clean a swing set. We found that this washer's variability makes it the most versatile unit in the pack: It scales from cleaning the car to cleaning the whole house. [$450; generac.com]