I can't remember the company that I bought the fuel tank from, but it's very well made and fairly inexpensive. Capacity is 3/4 gallons, which for one rider while motoring alone should last about 125 miles. Don't know about two riders yet, and will have to do some tests. I rode down to the local Chevron station yesterday to fill up. Got a few looks from others, naturally. $2.40 to fill up. The weight of the engine vs. the tank on either side balances out pretty well. There's no perception of the bike being off balance.