I'm new to this site, and I've already learned some things. Like the Fram oil filter I have on my '99 Sable is junk. It's running 5w-30 M1. I have aroung 2k on this setup now, and from what I read, I can go 5k. But the filter is crap, and I don't want to change the oil. So I am going to put a Purolator Plus on. When I hit 5k, it will be springtime and warmer weather, so I'm thinking of going to Motorcraft 5w-30 with a Purolator Pure One or a Motorcraft,. Then I'm going to do the 3k OCI untill next winter, and return to M1 for the entire winter (5k). Does this sound good to you guys? Or should I stick with the M1 and 5k changes? Can there be any problems with changing oil brands every summer and winter?