Insurance replacing only two of my tires, is this right?

Hey guys, so my baby was hit while it was parked and the dunce didnt leave any information. Luckily, in my state, the insurance company still has to repair the vehicle. In a recent talk with the adjuster, they mentioned that they were going to be replacing two of the tires. I told the guy that since it was a Subaru they have to replace all of them, yadda yadda. He said that he measured the tread depth and that it was within allowable limits, but based on my experience with this company so far, I don't trust them. When I'm going to pick up my car, I'm going to ask them to put it on the lift so i can directly measure the circumference of the wheels rather than going off just tread depth. What is the actual allowable difference between wheel circumferences? Also, does anyone have a link to a Subaru technical manual I can bring with me to prove my point? Thanks.

There is some information on the Subaru Tech Line re:tire replacement which states that the allowable difference between all four tires should not exceed 0.25 inches in circumference. This is extremely tight, BTW. The way to measure this is not to go from tread depth, but to measure the tire circumference with a tape measure with all tires inflated to the same pressure.

 

Subaru in their owner's manual recommends all four tires be of the same size, make and model.

 

It may be more effective to have the new tires shaved to make them the correct size, instead of replacing all four.

 

However it is done, it is very important that the tires are the same size because doing otherwise can damage the AWD system.

 

More info here:

http://legacygt.com/forums/showthread.php/do-you-need-replace-all-your-tiresii-read-first-before-105336.html

Just out of curiosity, how many miles do you think are on the tires? How long have you had them? The link miles posted has everything that you need, but I'm just curious because I'd really be pushing them for 2 more tires..