[urq] Mixed Wheel Widths on Torsen Cars? No US urq content...

[urquattro at comcast.net]

Those of you with Torsen centers in your cars; any experience or stern advice on mixing wheel/tire widths front to back? 
There's a decent deal locally on a mixed set of wheels I'm interested in, 8.5x19 on the front, 9.5x19 in the rear. By my quicky calculations, using 225/45 in the front and 255/40 in the rear on 19" wheels should (in theory at least) get the total diameter within .06 inches, or 0.2% of each other. Seems like you could pretty easily have at least this much variation in front/back rotation just by curved roads and I haven't heard of that ruining any cars yet...
Any thoughts appreciated...And don't worry urq purists; this isn't for the urq; it's for the blimp I drive when I have the family along!
-Jon