I close mine when I am parked for any time. when driving I leave the valve open. I was having problems with the oem tank losing fuel due to heat expansion when full.
Gravity feed system is DOT legal. This has been discussed many times over. Not legal for gasoline. Literally thousands in use. There is a check valve in the vent in the event of a rollover as well as a check valve in the fill hose. I'm installing mine in its' second truck. One of the best things I've bought...DonJust curious about legality of the gravity fill system. Or, at least the safety.
If the gravity tank is illegal then why do the manufactures keep building them? No bashing here just a simple question.
RDS 37 gallon tank. Gravity fed. Simple and works great. Only holds a true "32 gallons". But 32 gallons gets me another 350 miles.