Not to highjack this thread, but I also do alot of highway driving and have a problem with inner tire wear. I've recently had the local tire shop do a Toe alignment to my specs. Now the front is set 1/16" Toe-In instead of the factory spec of ~1/8" Toe-Out.
I did notice it lost some smoothness on turn-in on tight corners and doesn't have the same overall handling characterist as before. However, on the highway the straight line driving is fine and it tracks well. I guess only time will tell if this going to help prevent the saw-tooth inner tire wear. I'll be sure to post an update after I log some miles.
