Same thing happened to my SVT; wife put 12 gallons of 87 octane in it. The major problem was that after I raised much hell with her and told her she could never drive it again, I couldn't tell the difference! Must have great knock sensors on an SVT! BTW, I didn't tell her that I couldn't tell the diff.

John
Black '98 CSVT
#2000 of 6535
Sometimes good, sometimes bad
Sometimes hate it, mostly love it
No mods other than 225/45-17 tires