What is the wrench size to remove oil drain plug from 2006 Ford Escape V6?

I read that the V6 uses 15mm...I am not sure about the 4-cyl, though. ref.: http://www.dennisjudd.com/2006/05/oil_change_on_a_2006_ford_esca.html ---------------------------------old answer below--------------------------------- I have both US and metric wrenches and neither seem to fit very good