Originally Posted by
HaikoW
The above table states when upgrading from U-class earning is 100% miles and when one is upgrading from Y/B-class earning is 125% miles because being booked in Z-class.
I do not think so. The number of miles earned always depends on the original booking class before the upgrades. So IIRC the percentages for Economy, it's 100% for Y B M and 75% for U.