O.K. I just pasted this here from another thread I replied to, this is why I won't run a 225/40 on a stock MS3 wheel..."When you combine the width/aspect ratio you get the bead of a cross-ply tire. It consists of bundles of bronze coated high tensile strength steel wire strands which are insulated with rubber. A cross-ply tire designed for off-road use typically has two or three bundles. A radial on-road tire normally only has one. The bead is considered the foundation of the tire. It anchors the bead on the rim. That's why you just can't look at the numbers individually, they need to be looked at together to determine the appropriate size wheel. Look at the link and plug in the 225-40-18, minimum width rim is 7.5", now plug in the 225-45 minimum is 7". I know people run this 225-40 I for one won't take a chance on that size on the stock wheel. My tires are the first thing between me and the road...nobody in the tire service industry will recommend a 225-40-18 on a 7" wide wheel, there's a reason for that"...
The link I was referring to was Tire Rack. If you go to Tire Rack or any other tire seller plug in the numbers and you'll see no one recommends a 225/40/18 on a 7" rim, period.