Can an auxiliary in-bed fuel tank be plumbed in using the gravity flow method?
It is extremely easy to plumb in an aux tank using gravity feed. Before doing it, make sure it is legal in your state. Understand the fine print if they say it is not legal. The problem in most states is how it is done, in other words how is the tank hooked up. Most OTR large trucks use a gravity line between their saddle tanks to move fuel from one tank to the other, and there is the secret in most states moving the fuel from the aux tank to the main tank, not directly to the engine. This method requires no cutting of fuel lines, no pumps, no electric switching valves. The third gen Dodge has a non-vented fuel cap, meaning fuel will not flow out of the cap. Therefore, fuel will not run out of the cap even when the fuel filler pipe is full to the top with fuel. However, most second gen trucks will find this method will work on their setup also, however more care should be followed in the use of the tank. Most auxiliary tanks have three ports, two high on the tank and one low: a siphon
