Draag is responsible for about 70% of all fuel needeed to move a car like XJ, it doesnt matter if its heavy or not. In an average ride you´ll never use more than 1/3 of power or torque, so there´s no way to improve mpg unless changing the shape of the car, even addind more lentgh in the intake...
I live in Brazil, and here I cant find the cluster lens for a 98 XJ, broken when replacing the 4wd bulb. If someone tell me where to find...
Thanks in advance for any help!!