Over the weekend I rented a rototiller rather than buying one. The only way the rental agency would rent it was to take it with their tractor, a JD 4200. It was way underpowered for the 3-point tiller. When comparing it to my JD 4520, it was like comparing a 60s VW bug to my 8.1 L Suburban. But, of course, the normally aspirated 4200 would, no doubt, perform better at sea level than at my altitude, 6,500 feet.