Editing Tractor (section)

=== Engine and fuels ===
The predecessors of modern tractors, traction engines, used [[steam engine]]s for power.

==== Gasoline and kerosene ====
Since the turn of the 20th century, [[internal combustion engine]]s have been the power source of choice. Between 1900 and 1960, [[gasoline]] was the predominant fuel, with [[kerosene]] (the [[Rumely Oil Pull]] was the most notable of this kind)being a common alternative. Generally, one engine could burn any of those, although cold starting was easiest on gasoline. Often, a small auxiliary fuel tank was available to hold gasoline for cold starting and warm-up, while the main fuel tank held whatever fuel was most convenient or least expensive for the particular farmer. In the United Kingdom, a gasoline-kerosene engine is known as a [[petrol-paraffin engine]].

==== Diesel ====
[[Dieselisation]] gained momentum starting in the 1960s, and modern farm tractors usually employ [[diesel engine]]s, which range in power output from 18 to 575 [[horsepower]] (15 to 480&nbsp;kW). Size and output are dependent on application, with smaller tractors used for [[lawn mower|lawn mowing]], landscaping, orchard work, and [[truck farming]], and larger tractors for vast fields of wheat, corn, soy, and other bulk crops.

==== Liquefied petroleum gas ====
[[Liquefied petroleum gas]] (LPG) or [[propane]] also have been used as tractor fuels, but require special pressurized fuel tanks and filling equipment and produced less power, so are less prevalent in most markets. Most are confined for inside work due to their clean burning.

==== Wood ====
During the Second World War, petroleum-based fuel was scarce in Europe, so European vehicles including tractors were commonly converted to use a [[wood gas generator]] or "gasifier."<ref>{{Cite web|title=Wood gas vehicles: Firewood in the fuel tank|url=https://www.lowtechmagazine.com/2010/01/wood-gas-cars.html|
archive-url=https://web.archive.org/web/20220221205156/https://www.lowtechmagazine.com/2010/01/wood-gas-cars.html|archive-date=2022-02-21|access-date=2025-03-08|website=Low-Tech Magazine |date=18 January 2010 }}</ref>

==== Biodiesel ====
In some countries such as Germany, [[biodiesel]] is often used.<ref>{{Cite web|url=https://www.inforse.org/europe/dieret/altfuels/biodiesel.htm|title=BIODIESEL|website=www.inforse.org}}</ref><ref>[https://web.archive.org/web/20120320080038/http://www.bebioenergy.com/documents/BallaratUniversity.pdf BE energy promoting biodiesel for use in tractors]. Department of the Environment and Heritage, Australila</ref> Some other biofuels such as straight vegetable oil are also being used by some farmers.<ref>[https://web.archive.org/web/20101113115326/http://articles.cnn.com/2008-08-08/living/farmer.fuel_1_jatropha-diesel-fuel-biodiesel?_s=PM:LIVING Jatropha being used to run a tractor]. ''CNN'' (2008-08-08)</ref><ref>{{Cite web|url=https://extension.psu.edu/forage-and-food-crops|title=Forage and Food Crops|website=Penn State Extension}}</ref>

==== Electric powered ====
Prototype battery powered [[electric tractor]]s are being developed by a German company, [[Fendt]], and by two US companies, [[Solectrac]] and Monarch Tractor.<ref name="Gaines"/><ref name="Weisbrod"/> [[John Deere]]'s protoype electric tractor is a plug-in, powered by an electrical cable.<ref name="hobby20020723"/> [[Kubota]] is prototyping an autonomous electric tractor.<ref name="Szymkowski"/>