24.7 Fuel: range and gas cans

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Calculate each car's range

Look in the manual for the tank capacity and the highway fuel economy (mpg). Usable range = tank gallons × highway mpg × 0.7. The 0.7 factor is a margin for slow traffic, air conditioning on max, a heavy load, and not arriving on an empty tank. Write it on the plan sheet.

Calculate each car's range
Item Car 1 Car 2
Tank capacity (gallons)
Highway fuel economy (mpg)
Usable range = tank × mpg × 0.7 (miles)
Range from half a tank (miles)

In a convoy, the convoy's range is that of the car with the shortest range. Plan your gas stops around that car. Fill up every chance you get when the tank is below 3/4: in an evacuation you do not know whether the next gas station will have fuel.

Gas cans

DANGER: GASOLINE FUMES IN A CLOSED VEHICLE

Gasoline fumes are flammable and toxic. In a vehicle whose cargo area is open to the cabin, the cargo area is part of the cabin: a can there is a can inside the car with the people and the pets. Never carry it in the cabin or in the cargo area.

Only cans approved for gasoline (with UL certification or an ASTM label), in good condition, with no dents or leaks.
To fill it, set it on the ground, never inside the car or in a pickup bed, with the nozzle touching the rim of the can. Engine off, no cigarettes.
Fill it to no more than 95% to leave room for heat expansion.
Transport it outside the enclosed vehicle: on a securely fastened hitch-mounted cargo carrier, if your vehicle supports one. If your car has a trunk separate from the cabin, that is less bad than the cabin, but it is not recommended: if you have no way to carry it outside, do not carry it.
Secure it so it cannot slide, and wipe it clean before loading it. Do not leave it in the vehicle for long periods; take it out when you arrive.
A safer alternative: travel with full tanks and plan your fill-ups instead of carrying extra gasoline.