I just purchased my 2nd SVX, a 97 with 25k and I asked the same question of a subaru mechanic (I blew the tranny of my 92 at 87k). He suggested the original SVX transmission cooler/filter got clogged with debris over time and caused the transmission oil to overheat. The tranny was later redesigned to avoid this problem. I am still considering synthetic oil and an auxillary cooler.