Auxiliary Diesel Tank Gravity Feed vs. Electronic pump

You might be better off replacing the small factory tank with a larger one, to keep all the weight as low as possible.

I thought that it was Federal laws that prevented gravity flow systems. Something about some vehicles leaking fuel after a collision that caught fire, and all that. Our Government wants us to stay alive, so we can keep paying taxes. . .

Really, new regulations from the EPA say that a fueling system can not evaporate more than a few grams of fuel each 24 hours. While before 2004, a Ford truck could allow up to 30 grams of fuel evaporation per 24 hours, after 2005 the limit was much stricter 10 grams per day. You can thank an environmentalist that your car is now safer, and will not vent fuel into your garage at night. Sure the car will cost $800 more, but it is safer! And will not leak out 10 ounces of fuel vapor per month in the summer time anymore. .

So do you have the weight capacity to carry a second 50 pound fuel tank with another 300 - 400 pounds of fuel in it? If you had a gas truck the engine is lighter, and you might get away with it.

Fred.

I have a 60 gallon RDS gravity flow tank. Gravity flow is legal with tanks such as RDS. They are DOT certified and so on. They drain into the factory fuel tank and have roll over shut off protection. The sites which sell the models with the electric pumps like to say that gravity flow if illegal. They are right if the tank is connected to directly to the crab or injectors. I guess you mount those tanks on the roof of your truck. Anyway RDS and the other gravity flow tanks marketed today are fed by way of a shut off valve to the main tank. Legal and safe. When I travel I run with my aux tank open and flowing into my main tank when my gas gauge starts to move I know my aux tank is empty. The tanks with the electric pumps work fine and also are legal and safe. The disadvantage for me was they cost a whole lot more and I have another electric pump to replace if it fails. Either way you will be fine. You will also not miss filling up every 250 to 300 miles when traveling.

About 6 years ago, 2008, I had a professionally installed system put in a 2006 Dodge. Electric pump, filter, fuel level gauge. Nice system. Ultimately it pumped into the OEM filler tube.

In 2010 I bought a new truck. I transferred the tank to the new RAM and simply hooked it up as a gravity-fed system. It's not as fancy, but it works just fine and is much easier to remove if I need to.

The only issue is that when both are full and the auxiliary tank shutoff valve is open, I cannot remove the factory fuel cap or fuel will come out.

I had mine installed in Elkhart, IN by the Dually Depot. Nice professional folks.

I know this isn't what you asked but when I had my 2500HD Chevy, I couldn't put an auxillary tank in as my pin weight was already over the trucks 2000 pound load limit.