When I lived in northern Minnesota in the 70's, many car owners regularly got 200K miles on their engines before overhaul driving down gravel roads and using dino oil. Regular oil and filter changes are the key. The dino oil of today is even better. I'm switching to Castrol GTX High Mileage oil at 150K. I'm at 146K and Castrol 5W30 kept my engine in great shape with 5K oil/filter change intervals.