It seems the toe in was was out in the front of my 05 Outlander LS AWD and the front tires are badly worn at just 18000 miles. I guess I need to pay better attention. :unsure:
I know for some older AWD vehicles it is necessary to replace all 4 tires but is it required for mine?

Thanks in advance.

you should be alright replacing the two bad ones on the front, as long as the rears still have sufficient tread. just be sure you replace tires at least in pairs; fronts, and or backs. because of road hazards, i was almost only replacing tires on my '93 expo, which has 255,000 miles on it, in pairs, newest on the front. i usually gave a careful look, at the front tires anyway, whenever i changed the oil. you should be OK, just make sure the alignment is corrected, and rotate the tires a little more often. good luck!