The fl2124s I purchased was a little cheaper at only $22.97 at O’Reilly. You don’t see a price cheaper than amazon very often.
On FL500s I just heard of people going to dealerships and getting the new filter and being told they don’t have the FL500. I could be wrong and if they are interchangeable maybe dealers just decided to keep the new one.
So basically when dealers order filters from Ford we have to order case quantities. Not all filters we want to keep a case of, think cabin filter for a Windstar. So we order smaller than case quantities from companies called FADs, Ford Authorized Distributors. Not all of them carry everything. I am lucky in that my facing FAD carries the normal filters as well as teh alternate numbers, so I can almost always have stock on hand to take care of my customers, my biggest by far being our service department.
The 2051S was on backorder for a few months before the 2124 started being a thing. I always kept more than I should for those filters in stock since it looks bad to tell a customer we can't do an oil change on their new Super Duty because Ford can't supply us with parts. Same as when the FL-2087 filters for the later GT-350s and the Predator engined GT-500s were on backorder.
They automatically update the order to the 2124S when I try to order them. The MU2Z-C number is the long number for the 2124S.
I ordered mine through Amazon. None of the local places ever have my filters in stock.
