Originally Posted by Platinum_Sean

That's because you did not chose your tires properly!!

If you have 265 65 18 for example, a tire size of 275 55 20 will have about the same dimensions (within 2%) thus, the speedo, odometer, and overall heaight will be close to OEM. Rims are only 1 dimension.

Re: sidewalls riding harsher- I'd challenge anyone to blindfold themselves, get in to 2 identicle trucks. 1 with 55 profile, 1 with 65 profile and clearly identify the "harsher" ride. Ain't gonna happen.

Use this site to size tires:

http://www.dakota-truck.net/CGI-BIN/TireCalc.cgi