$17 5 quarts Valvoline dinojuice + 1 orange can of death
$10 gallon Valvoline diesel dinojuice
No $5 5qt oil at the West Warwick, RI location. Doesn't matter for me, I don't have any vehicles that I'm willing to put just any old random oil into...I'm more careful with a 200,000 mile old truck and a 30 year old car, and the VW has warranty requirements as well as the manufacturer's recommendations.
I certainly advise against using a lesser oil than the manufacturer specifies.
I would say that the worst oil on the market now is probably far better than the best oil that was on the market when your Buick was new. That being said, I have only used 3 oils in my Buick since the engine was replaced about 15 years ago. I used Valvoline 10W 30, then switched to Mobil 1 10W 30 about 10 years ago. About 2 years ago I switched to Mobil 1 5W 30 Extended Performance.
I agree, if I found oil in the dollar store I'd expect it to be no worse than the oil that was around 30 years ago. If the car came through a time warp and has only existed for a year then I'd throw any oil into it.
However, after 30 years seals are suffering, metals are corroding, etc...I figure it needs High Mileage oil (even though it only has ~38,000 miles).
that's funny 'cause that's the exact ad i found online for my area. but the hard copy in the newspaper had more items, like said $5 5qt motor oil. it may have been a gal size, but i distinctly remember the price because it was "Peak" brand--the antifreeze maker.