Originally Posted by
xliioper
Not my experience. Here are a couple fare differentials on DTW-MSP (L and T fares) from EF. The $80 and $90 seat upgrade offers (total $170) did not match the $130 fare diff (which can't be split across segments due to being single fare component).
It's per-segment.
Not sure if you were going into Z instead of P, or if the tables are using the differentials to BE. MSP-ORD is a $60 differential ($90 to BE) and DTW-ORD is $50 ($80).