I finally gave up on trying to decide which oil to use, and just bought the cheapest 10W-30 Walmart sells, which was Quaker State, which is light years ahead of what they had back in the day. I'll be lucky if I see a 100 miles between annual oil changes anyway.
Not being a tribologist I'm somewhat with the above. We bought a new Dodge Dynasty for a family car back in 1988. Being thrifty by nature I changed the oil every 5,000 to 7,000 miles using Walmart oil (which at the time was made by Quaker State). Don't remember the weight but it was likely 10w30. The car died in about 2003 with over 300,000 miles due to a non engine wear related problem.
No more miles than most of our trucks go between changes, most any oil with at least a 10W on the low side (if multi viscosity) will be fine.
