That is interesting. Just before I quit my part-time job at the W-M TLE, I DID notice that the Pennzoil oil filter looked different on the bottom.
A couple of months after I left, I stopped by the shop, and noticed they had STOPPED using Pennzoil filters - all they had on the shelf in the shop was orange Frams.
I guess the new Purolators were more expensive, and Wal-Mart wanted to keep the price low on their oil changes, so they just went with Frams, which are all they have on the customer shelf anyway.....