Welcome to the world of diesel-powered "smoker" pulling tractors, where too much of anything, especially turbo boost and wheel-speed, is never enough. These are among the most incredible vehicles in ...
The 20 series of John Deere tractors began with the introduction of the 420 Model in 1955. The next year the 320, 420, 520, 620 and the 720 came along and in 1957 along came the 820. The most common ...