Does anyone know what the general rule is for Canada/USA for custom fuel tanks if you put them in yourself and do not plan on selling the vehicle? Putting an HDPE tank with steel armour underneath in each wing would really help range and would also keep the weight low compared to stacking the rack with 20l cans. Would also be a whole lot easier to fuel from and refill.

 

The regulations regarding aftermarket fuel systems that you'd have to meet are : FMVSS 301 (Federal Motor Vehicle Safety Standards), VESC-22 (Vehicle Equipment Safety Commission), NFPA 1192, ANSI 119.2, RVIA (Recreational Vehicle Industry Association) regulations, CARB (California Air Resources Board, assuming you are in Cali), and EPA (Environmental Protection Agency) regulations.

FMVSS 301 states that anyone who alters a vehicle must meet or exceed the structural integrity and performance of the OEM (Original Equipment Manufacturer) fuel system. In other words, if an alterer adds an auxiliary system to a vehicle thereby reducing the performance of the fuel system, he or she has violated FMVSS 301 standards.

I say go for it. I was considering removing my rear seats and building a steel tank to fill the rear foot area. Keep us in the loop if you go for it, I'm sure many others would be interested.

 

Some more info:

1. The 1990 Clean Air Act states that an individual owner of a vehicle may modify his fuel system only if it complies with all federal regulations. If he does not, he will risk state and federal penalties.
2. When an auxiliary system is added to a gasoline powered vehicle, the fuel must be drawn through a pipe at the top of the tank. Balance lines or tanks in series so that one tank supplies another is not permitted. Gravity feeding from one tank to another using a balance line is illegal for all systems except ICC diesel systems.
3. Replacement systems are acceptable as long as they meet the previously discussed regulations.
4. Should non compliance with FMVSS or the 1990 Clean Air Act be discovered, the owner would be liable for civil penalties up to $2,500 for each violation. Also, the Federal Clean Air Act requires manufacturers to exercise more care in their product applications to avoid violations of the law. Violations can carry penalties up to $200,000. For example, adding a fuel system that does not meet provisions for proper emissions control could be in violation of the Federal Clean Air Act.
5. Fuel line routing should allow for a minimum of 3 inches of clearance from the exhaust system or else a metal shield must be provided.
6. Fuel lines should never be routed on the outside of the vehicle body.