Well, WAG7s scheduled POH time is 9 years +/- 3 months and its 12 years for WAG9 and the WAG7 POH seems to be on schedule. No surprises here. :) Besides, POH cost will be more for replacing parts in 3 phasers than conventional locos while maintenance schedules will be tighter for conventional ones. The Traction motors are only one side of the coin.