I'm doing my first oil filter change on D25U4467 ("Irma" as in Irma La Duce) and I went to my Wix dealer and they gave me their no. 51161 as a replacement part. When I removed the original I see that it has a rather intricate outer filter that is washable and a throw away inner filter. The Wix 51161 replaces both of them. Does anyone feel that this is an unacceptable move? Thanks.