Hello ,

Just wanted to know if someone as already tested the fuel capacity of the tank , in order to know if I must hurry to fuel pump as soon as the low level light goes on !

drivers doc said 85 liters with 5 liters when light is on ( which is quite low for big engine car ! )

last time I feed that big cat light was on for at least 15 km , computer said 75 km remaining fuel , and i could put only 69 liters !

2 possibility , there were till 15 liters in the tank ( enough for 150 km )
or the tank is 75 l instead of 85

 

JTIS on a 04 XJ states 85 liters is "Usable fuel tank capacity".

 

From the Technical Guide

Fuel tank capacity:
– normally aspirated 85 liters (18.7 gallons),
– supercharged 84.5 liters (18.6 gallons).

I presume the difference is due to the second fuel pump on the S/C.

The low warning light is intended to come on when there is around 10L of fuel left in the tank.

The guide for the diesel says that it also has an 85 litre tank but there is a run dry strategy that cuts the engine when there is around 4 litres left in the tank.

Another interesting fact I spotted:

On S/C vehicles with twin pumps, they are fed by two separate fuses F24 and F33 in the rear power distribution box.

If either pump fails to work and the tank is below half full, the operating pump will transfer fuel to the other side of the tank, (faster than it can deliver the fuel) causing the vehicle to stop running.

If the tank is above half full the vehicle will continue to run but will not make full power. The fuel gauge will drop to zero and there will be a reduced power message.