The company's first fully green-and-yellow tractor was the Model "D" that sported 15 drawbar horsepower
. Today, John Deere builds dozens of different tractors--ranging in size from its smallest 1023E Sub-Compact Utility Tractor with 23 horsepower, up to its massive 9R Series Tractor with 620 engine horsepower.
But size is subjective: do you go by weight comparison, drawbar horsepower
, tire/wheel size or price?
Subcompact tractors are designed to convert more of that engine horsepower into ground-engaging pulling power (drawbar horsepower
1981 -- The heaviest wheel tractor that has ever been tested was a Big Bud 525/50 developing 421 drawbar horsepower
and weighing 51,920 pounds (23,364 kilograms).
* Drawbar horsepower
: Power available at the drawbar of the tractor to pull equipment.
Maximum drawbar horsepower
was recorded in second gear with 44.64 hp and a pull of 4,863 pounds, well above the advertised ratings.
For average depth stubble plowing (relatively light duty), about five drawbar horsepower
are required of a tractor for each 14 inch bottom or blade of the plow.
Huber engineers estimated with a Continental H243 gasoline engine running at 1,600 rpm, the tractor would have developed drawbar horsepower
of 39.40 and 44.86 on the belt.
Today there are four "categories" of three-point hitches, based on different ranges of maximum drawbar horsepower
. The standards specify the dimensions related to the three points where the implement is connected to the tractor, minimum units for lift height, lateral leveling adjustments, side sway, and the minimum lift force to be available at the hitch pins.
Kerosene was used as fuel, and the tractor's drawbar horsepower
was almost 53 hp, far above the rated 40.
It used a 4-cylinder GM 276-cubic inch engine with 4-by-5-1/2-inch bore and stroke, and had 11.5 drawbar horsepower
and 19 at the belt with the engine running at 1,100 rpm.
It had 52 drawbar horsepower
and sold for $1,350 in 1940.