I hit 30k in my 2021 Prius and am doing my first oil change on it. I went into the store the other day and provided the make and model and they asked me if I have the large (Fram S4967) or small oil filter (Fram S2878)? Wth!?!? Really? Never heard of there being 2 options for oil filters. I would obviously want the larger, but after they showed me the 2 different sizes I wasn't sure they were interchangeable. So I went home to check which one is on my car and I discovered it was the small one. Figures. They said the large one had the same threads, but upon inspection the O ring was slightly larger, not much, it appeared it would overlap the O ring on the small filter and will more than likely fit. But the canister itself was probably an inch longer and an inch larger in diameter and I am not sure it will fit. Before I purchase one to try it, does anyone know if these filters are interchangeable? Did Toyota change their oil filter mount at some point in 2021 so accommodate the larger filter?