The rule of thumb is: You burn one lb (unit) of fuel for every three lbs (units) of fuel you carry. Me: FAA licensed dispatcher (Also, you'll see a 1:1 rule

The rule of thumb is: You burn one lb (unit) of fuel for every three lbs (units) of fuel you carry. Me: FAA licensed dispatcher (Also, you'll see a 1:1 rule would imply adding fuel does not increase range, which is absurd.)