FarmVille is having a special event for the first time and it will allow players to use their Tractors, Combines etc with out any Fuel for a whole day. It will be scheduled on May 26, Monday and it will start at 12 AM in PDT.
During this time any vehicles you have on your farm that uses fuel will not require or consume a single drop of fuel when used. You can use it for unlimited time during the event.
FarmVille already setup an event page on Facebook. You can visit the event page in order to view the status of the event and you can also click the join button in order to show that you are interested on joining the event.
You can visit the event page at https://www.facebook.com/events/1417474695196368/#!/events/1417474695196368/.