Originally Posted by VWang1111

Quick rundown is EWR-LAX and EWR-SFO direct is a premium flight so no one gets free upgrades. That route only supports instrument upgrades where you apply miles to get on the wailist. Other domestic routes support complimentary upgrade where you are on the upgrade wait-list without adding miles. As a silver, you can check your position within 24 hours of the flight to see where you are on the list and the earliest you can be upgraded is T-24hr of flight departure. Note as a silver, upgrades are extremely hard to come by unless the flight is completely empty. If you use miles on a flight that offers complimentary upgrades, you have higher priority than all other complimentary upgrades including top status like 1k.