Sorry to thread jack but I have a question. I just went from 27in to 31in tires and a 4.5in lift. I was getting 300 miles on a tank and now I'm getting 140 to 150 on a tank. Is that normal? Its a 96 XJ 4.0 and auto. Every sensor is new,so is the cat and cat back. I just had it E-checked and they said it runs cleaner than most 3 year old cars they've tested. So whats the deal? It has a 20.2 gal tank and runs like a rapped ape.