I've tried replying to your question a few times but it's not showing up in my messages as ever being sent. Please let me know if I've sent you the same thing several times and I'll stop trying. But here's an answer to your question...
My wheels are KMC XD Addicts 18x9 with +18 Offset. My tires are 275/70/R18. I calculate my new wheels/tires stick out 1.1 inches more than the stock set. No rubbing issues so far.
My average MPG was 16.4 before the tires. I've only done one tank of gas with the new tires and I got 15.75. That includes correcting for the bigger size of the new tires. You can ask me in a month or so and I'll give you an update on my fuel mileage. I keep track of every tank with an app for my phone called "Road Trip" so I'll know if the mileage gets worse or better.
Also, Goodyear has a rebate on tires right now through the end of the year. It's either $60 or $80, I don't remember, but it's on their website.