Checking LAX-BOS today on dot bomb, I was offered a nonstop, at 2611 PQMs (the same as Great Circle mapper shows), or some one-stops. One could connect through either IAH or ORD, which should be 2976 and 2611, respectively. However, UA lists the first batch of the itineraries as 2611 miles. The site says: 1 Stop. Time on the ground in Chicago, IL (ORD - O'Hare) is 3 hours 4 minutes. Change Planes. Equipment changes in Chicago, IL (ORD - O'Hare) to a Boeing 737-900. Then, there are several flights listed with the mileage I would expect (full GCMapper miles), and notes like this: Change Planes. Connect time in Houston, TX (IAH - Intercontinental) is 1 hour 19 minutes. I do not understand what the rules are here. What's the difference between stopping and having your equipment change vs stopping and changing planes? Why would you not get credit for the miles flown?