Is there a chart that shows the various model numbers of JD tractors and the amount of horsepower they have? Or is there a rule of thumb that a novice can follow as to how much horsepower a tractor has. I see comments all the time about various models and what they are capable of but I do not know what horsepower that model has. I think it would be nice to print out a simple chart as to model and horsepower if one is available..