Farmville vehicle question?

If I were to buy all three vehicles (tractor, planter and harvester) they would each have their own fuel gauge, or are they all share? So basically it's a waste of money to buy all three since I have missed energy using a single vehicle.

thus, they share a tank. but you must buy three .. for plowing, sowing and harvesting. when I mine I usually divide it into 50. 50 per tractor, planter and harvester

Farmville Super Combine – Harvester, Plow, and Seeder all in one click!