Really?You missed my point AJ. Before the oil refinery upgrade the fuel timer was 90 seconds for one unit. What is the point of doubling the capacity if it takes twice as long to fill the tank. Regardless of tank size you are still only auto generating the same amount of fuel per day. The secret faucet doesn't decrease the time, rather it gives 2 units every 3 minutes instead of 1, which by the way, was the original productivity of auto generated fuel, 2 units every 3 minutes.
Mine fuel timer was 3 minutes before building small oil refinery lvl 1 and it stayed 3 minutes even after making small oil refinery lvl 1.