The E33 (Ca model) has a fuel vapor seperator unit and attached breather tube inside the fuel tank leading out to the charcoal cannister alongside the frame. Hence the 5.3 gal capacity instead of the 5.8 of the 49 state models. I took all the emission stuff off mine because my tank whistled from the pressure . I checked the one way vapor valve and all the stuff and could not get it to relieve the pressure so just took it all off, blocked the line going to the purge valves, saved weight too. You can't get around the capacity, it is designed inside the tank.