How does it make any sense that Ford's OEM fuel tank for a V10-powered extended van with a tow package is about 30 gallons?

Seriously.

Hook up a 9k lb trailer and you're refilling every few hours of highway travel.

Ford used to offer dual gas tanks on E-Series vans back in the day, is there any supplier that offers an auxillary aftermarket tank for late-model E-Series vans?

I see aft-axle and spare tire aux tanks for earlier years... but nothing for my 2012 vintage.

Isn't my chassis the same chassis as earlier F-Series super duty pickups? Would an aux tank for a 2WD F-350 truck fit beneath?

 

I towed a travel trailer with my E350 V10 and I could go all day without buying fuel. I carried a Jerry can and would transfer it to the van at the lunch break. I could travel over 450 mile a day which was plenty for me.

 

Maybe I was exaggerating too much. I probably drive at 65 mph with a 9k lb trailer for four or five hours before refueling. Still, a 50 gallon tank is way more appealing than carrying spare gas cans. :P