Our 06 touring came w/ pax and the rims were 18.8 in diameter. I would imagine yours are the same. You might see a slight difference in handling going down in size. Anything is going to be an improvement over the pax. The inside of the pax wheels have a raised nylon/composite type ring which is essentially what you would ride on in the event of a flat. Combine that w/ the tire construction itself and you have a heavy, harsh riding, and loud rim tire combo. We depaxed to 245/45/19 and the ride is substantially better. Better handling, much quieter, and it no longer rides like a train. Plus the aftermarket rims and tire were a fraction of the weight. Just do your homework and know what you're looking for before you talk to any shops. The local shops around here were less than helpfull and either tried to sell us something we didn't want or said they can't remove the pax system.
I would start here for sizing and wheel info they have great calculators to figure size and offset, http://http://www.1010tires.com/tiresizecalculator.asp
I would start here for sizing and wheel info they have great calculators to figure size and offset, http://http://www.1010tires.com/tiresizecalculator.asp
