Most minivans have a fuel tank that can hold between 15 and 20 gallons of gas. The number of gallons of gas a minivan holds depends on the make and model of the minivan.
Based on a 2012 comparison of some of the top minivans, the van with the largest gas tank capacity is the Honda Odyssey, which holds 21 gallons of gas. The comparison showed that the minivan with the lowest gas tank capacity is the Mazda M5, which holds slightly less than 16 gallons of gas. Several minivans, including the Toyota Sienna, Chrysler Town & Country, Volkswagen Routan and Nissan Quest, have a gas tank capacity of at least 20 gallons.