Hello. My car is a 1995 Buick Park Avenue with the normally aspirated 3800 Series II engine. I purchased new in March 1995. Dino oil used with 3,000 oci until 20,000 miles, then 10W30 Mobil 1 with 5,000 oci. Now has 260,655 miles on odometer. Never burned a drop of oil. One-hundred percent highway miles (first brake job at 180,000 and still running on that one). Heated garage and used only on weekends. I am intrigued by the 0W40 Mobil 1 that I am now seeing. Please advise if I can safely change-over to this viscosity, or should I stick with the 10W30. Thank you.