and appreciate your input! Scott, I do have a Bentley and will ceratinly investigate this (although it's pretty much limited to 55-60 only- not under 1st and 2nd acceleration.) Joe, I've continued to suspect the tires as well. This is the second set of rims and tires I've tried (first were stock "bottlecap" wheels, and second set are stock basketweaves w/ new tires.) It's still possible one of the tires are out of round or defective, and the guy on the Hunter did come highly recommended and seemed to know what he was doing...but still. Just don't want to start swapping good parts for good. If you have any other advice, let me know. Again, thanks!