The AD is an earlier version of the 2nd gen engine, around 2014-2015. Your AF engine is a later engine with a couple slight revisions to it. Overall, interchangeable within the 2014-2019 family. One notable difference is the oil capacity - early AD took 8.5 quarts of 5w-30, instead of 10.5 of 5w40 that we all know now. basically, the oil spec was changed, the dipstick, and the oil fill cap were replaced.