Gasoline Transfer Tank.
Have any of you gas monkeys added a gas transfer tank so you don't have to stop every 200 miles or so when towing? I know auxiliary tanks are a no go for gas, but it would be nice to just be able ...
Forum Discussion
SoCalDesertRider wrote:Sport45 wrote:I have no idea if there is a law about gravity feeding to the engine in an on-highway vehicle. I don't know why anyone would be trying to do that on a pickup. The gas tank would have to be on top of the hood...SoCalDesertRider wrote:
The law is you cannot have a gasoline aux tank that gravity feeds into another gas tank (ie: feeding into the truck's main factory gas tank). It's legal to do this with diesel, NOT with gasoline.
Is that the law? I thought you weren't allowed to gravity feed to the engine. But I've been wrong before.
There are lots of stationary use engines that use gravity feed tanks instead of a fuel pump, such as generators, lawn mowers, air compressors, water pumps, etc.
I am thinking Sport was talking about gravity feeding the GAS TANK with a in bed aux gas tank.. Not directly gravity feeding the engine.
Gas has a higher expansion/contraction ratio than diesel..
Not to mention gas is more volatile and evaporates compared to diesel which is barely volatile and does not evaporate (spill some diesel and that puddle will be there pretty much forever).
Due to the high expansion/contraction ratio and fast evaporation it makes for a less than ideal fluid for gravity from one tank to another on a vehicle.
Not to mention, overfilling your vehicles tank with gas WILL result in the "evap" system taking on raw liquid gas instead of fumes, this WILL result in damage to the evap system ($$$).
The Evap system has a vent on the top of the gas tank, that vent is routed to the evap canister. This canister collects the gas vapors from the tank and eventually releases those vapors into the engine..
If one was to put a gravity fuel tank above the vehicles tank the evap vent would have to be relocated to the top of the highest tank..
Then there is the little matter of the vehicles fuel cap, one would have to lock it to ensure the cap is not removed while the top tank is full.. would kind of stink to lose 20 or more gallons of gas when someone who doesn't realize that the top tank is plumbed in and attempts to remove the fuel cap.. :E
