I have a 96 XJ, I want to put tires and rims on it but I don't really know what to put on. I would like to run a mud terrain with a good looking rim on it but still want to get semi good gas mileage.

Which is better for the XJ's?
Aluminum or steel with what tire set up and still get semi good mileage?

alloy/ alum is lighter. lighter is easier to move/ turn. this equates to better economy and power.

that being said good freakin luck getting good gas mileage with off road tires of any sort. especially without regearing. so in short it's a crap shot. buy whichever wheels you like. just google reviews on road manners and life span of various mud tires before buying

I think you'll find that the weight of the tyres will swamp the saving you make on the rims,even before taking into account the fact that the tyres are further from the centre of the wheel and therefore more important when calculating rotating mass.