Originally Posted by
Brendan88
I don’t know how many miles you have and how eager you are to spend them. In my experience you often get upgrade rates that are so high that you’d spend less miles on an award ticket in J than an upgrade from Y to J. I personally would not purchase a ticket with the thought of certainly upgrading with miles.
But the best way to find out if DL can upgrade you with FB miles is to give them a call. Upgrading before check-in is normally cheaper than at the airport (with some exceptions). You can also use them for an upgrade when onboard, but my experience is that this is more expensive than at check-in.
Thanks for all the responses! You're right Goldorak, my estimation is based on the seat map. I didn't realise that was an unreliable indicator of bookings, my bad. Anyway, as a data point for you all, I just spoke with Flying Blue. They told me that it would be possible to upgrade this Delta ticket with Flying Blue Miles but only if there is 'O' availability in Business Class. Right now there isn't any for my flight from JFK to CDG on Dec 15th. They told me that it's likely that more tickets will be released closer to the time. She also told me that with my Premium Economy ticket, I would be able to upgrade for 30,000 miles. I paid aprox. $800 return for this flight, so it seems like a pretty good redemption to me if the 'O' class tickets become available?