I cant see on a 12/13 where they could expand the tank?
Shrouds, like they do on the Hondas.
Factory GasGas has a 12 liter tank. Its over 800 bucks, I'm sure that is not enough capacity.
Oddly enough that looks like a Clarke tank. Check out the cap?
Also, i believe i can get close to 70 miles on stock. Here in the PNW thats a good long day.