A method for managing vapors generated by a first and second reservoir onboard a vehicle traveling on the road, the method comprising of inducting vapors from the first and second reservoirs during engine operation and reducing flow of vapors from first the reservoir to second reservoir and from the second reservoir to the first reservoir, wherein said reducing includes restricting said flow of vapors from the first reservoir to the second reservoir and from the second reservoir to the first reservoir to prevent fuel vapors with different alcohol amounts from mixing.