The 60L standard tank is a little small for long trips. The only real place to put an extra tank was behind the rear axle. Standard tanks on the internet were all too small in at least one dimension. I got a Stainless tank made that would make full use off the space. This tank would give me another 85 liters. A VETUS FTL3808 was used for all the connections. A marine sender unit was connected to a new gauge as the resistance was different from the standard Iveco sender unit.

To switch from the standard to the extra tank A POLLAK valve was used.

The one mistake I made in the design was the drain plug. This one sits on the bottom and sticks out a little. This could get caught somewhere. There was plenty of space on the side.