douglasr

I accidentaly fitted a space saver to the rear axle after a puncture. I e-mailed Torsen asking them what the potential damage would be. Here is the answer:

"We always abide by what the owner's manual states! We did a mini-spare tire test with a Camaro Z-28 and found no concerns with the Torsen T-2 in a rear axle. Damage that may occur are: if the Torsen is not lubricated, the differential will burn up and score the internal parts, and extreme differentiation due to the different rolling radius of the two tires will also cause the differential to heat up and damage the internal parts and housing.

Bottom line, follow what you owner's manual states for vehicle care.

Hope this answer helps."

So, it looks like its OK, but do as the manual says and change front to rear and put the space saver on the front like I did last night.