1.6 gallon (6 liter). Takes 83-up screw type gas caps. Fuel tanks are half way 3/8" internal threaded and 1/4" internal threaded on the rear end, on both left & right side. Approx. dimensions: 14.7" (37cm) long x 8.66" (22cm) wide. Tunnel dimensions: front depth 8", rear dept 1", 50mm wide. Tunnel width 2". Depth front 8", rear 1". Note: It is advised to pressure test, seal and test fit all tanks before tanks are painted and installed. Some tanks are painted, but this coat is applied for rust prevention during storage only. Note: Dimensions are approximate and for reference only.