I have startup noise on my 4 cyl Frontier. It is very bad after the vehicle sits for a few days. Within a very short time the idle smooths. The mileage is 50k and it has always had Mobil 1 5-30 at a 5k change. I have used Nissan and Fram ExtraGuard filters. My question is does anyone with this vehicle experience the same symptom and is there a better oil/filter combination? Being in Mississippi the morning temp is routinely never below 25. Any suggestions welcome. This is my first post and I will soon be asking a few questions as to Toyota. I have the Sienna and a Camry.