Well, the 5w30 is what you should be using, and a fram filter should be fine. The cold weather does have an affect on the oil. The colder it gets, the heavier the oil is at start-up. However, at 40 degrees, 5w30 shouldn't lead to the described problem. For the heck of it, try a motorcraft filter next time.
Keep an eye on the oil pressure to make sure it doesn't get too low. Your oil pump may be starting to develope a problem, but it's too early to tell.
Let me know if you have any other questions.
Wednesday, December 10th, 2008 AT 10:20 AM