I recently put a long range
tank on my hilux. It was fairly straight forward but the manufacturer advertised that the
tank held 144 litres. I filled
mine with 140 litres. The electric pump inside the
tank on
mine did not reach the bottom of the
tank due to a design error of the manufacturer. While I was filling it I checked the electric pump and it was sucking air for the first 15 litres. Consequently I only get 125 litres of usable fuel in my
tank. I was disappointed that I only got 125 litres having paid $1000. It is better than the 75 litres that comes with the hilux but is not what I paid for.
People have asked about the accuracy of the fuel gauge. The gauges are not accurate anyway but you can modify the performance of the gage by changing the length of the float arm. A longer arm will allow the float to rise to the top of the
tank. Be careful to measure the arm at the bottom of travel before altering it so that the empty position is always the same. Check the resistance empty and full by moving the arm through its entire range before altering with a multi-meter. The turn the
tank upside down and the correct orientation with the sender in the
tank and check the sender resistances again to ensure that the float is not fouling on something inside the
tank. If it is open, inspect, modify and try again. You will never get it completely accurate so make a note of where the gage reads as you fill it the first time. I have laminated a table of the measurements I got the first time and put it in my glovebox.