I drive about 30,000 miles per year...obviously mostly highway. I have a 07 IS350 with the Sports Package and stock 18 inch wheels.

I replaced the stock shocks and springs with F-Sport shocks and springs. Based on my measurements, the car did NOT drop any from the sports suspension. There was an alignment done at that time.

The past 20k have been split almost exactly between the two suspensions. With the sports suspension, the tires (Michelin Pilot Super Sports) I think the tire wear was even across the back tires. Now that wear has continued , with teh F-Sport suspension, it seems that I have more wear on the OUTSIDE of the tires. Yes POSISTIVE camber wear.

I wouldn't think that "aggressive driving" would be the cause as most of the driving I do is highway, straight line.... Any thoughts?

 

I am no expert, but using common sense it seems like you have positive camber. Tires usually only wear on the outside edge when it is mainly driven in the city (lots of left right turns). Get a free alignment check just to be sure.