I wanted to change from run-flats to standard tires, and at the same time, I wanted to increase the tire size and reduce the very harsh ride I was gettinging from the factory run flats. My BMW is a 2010 128i with the sport suspension and staggered 17 factory wheels(7 wide front, 7.5 wide rear). I also wanted a spare tire. So heres what I did. I went online and purchased two, new condition used, 7.5 facory wheels to replace the front 7 factory wheels($320.00). I used one front tire and wheel as the spare. I figured out how to strap the spare and jack kit down in the trunk but that's another story. I now have 7.5 wheels on both front and back. I had the Dunlop Star Spec 225/45/17 installed on the front, and Dunlop 245/45/17's installed on the rear. I was a bit concerned when I first started driving it in that it was so sensitive to the road, but after breaking them in with about 300 miles, I couldn't be happier. The harshness has been significantly reduced but it still has the traction and handling that you would expect from a performance vehicle/tire. It also looks FAT with these tires on it. I absolutly love it. I don't know how they will wear long term, but I will post again once I get about 10k miles on um. Oh, one more thing, with four people in it, you might experience a very,, very minor tire rub up in the fender well on the rear tires if you hit an aggressive dip. It's not very noticable,,, ever so slight. I experienced it once in 400 miles of driving. Not a concern for me. Could be more of a problem without a sport suspension. So if that's a concern for you, a 235/45/17 would probably totally eliminate that. Of course the trade off would be a slightly smaller tire. Hope this helps you.