Hell I ve only got like 500 miles on my xB and im driving uphill with a head wind most of the time with the a/c blowing between 70 and 80 miles an hour and still im gettimg 28 to 30 per gallon! I think you should have that car checked out! I'd also like to point out the mention of synthetic oil yes you can get better fuel milege using it and it will reduse the amount of engine wear and increase engine life!!! The picture of the spark plugs actuly looks pretty good when you sheck a spark plug it should have a light tan discoloration! if its black your could be burning oil if its whit you many be running to lean ( i.e.) not enough fuel something else that could cause spark plug problumes are the wires. So many people over look this spark plug wires today are not mad of hard wire like they one were, You see it interfers with the car radio! so insted they are a kind of carbon filld wire they work great! but iff you yank on the wire wrong or try to jerk it out you can put small cracks in the carbon and it can result in your car running pore rough idle a miss etc. I would see this all the time in idustrial applications with gennerators, where full power was constantly needed! i'm not saying go out and buy hard wires stick with the new types of wire just be a little more careful when removing the wires think gentle and always remove them buy pulling on the boot!!