Question for all engine Oil experts...

Given the fact that each one of our cars may require a different type/spec of engine oil, either be a Mobil 1, Straight 50, Valvoline, etc, etc, I was wondering if there is an commercially available Oil Spec that can be used on cars from the 70's (Charger V8), a Datsun from the 80's, a 308GSi, and a more modern M3?
Maybe there is an Oil out there with specs above all common minimum requirements combined.
In my case temperature range is 40F to 100F, in case it matters.
Reason is just simplicity of maintenance and keeping an inventory of all kinds of different oils for different cars.
cost is not a factor. Filters would be fine to have different filters for each car.
Any input would be appreciated. TKX

 

The only issue you may run into with the variety of vehicles you listed would be a weight that can handle the M3 but still give good pressure on the dodge. I've tried many different oils in my race builds over the years and keep coming back to Shell Rotella and Mobil 1. They seem to work for me. I run SR T4 15w40 in the Mondial it works well. Combing through the service history it was a buffet of oil choices depending on where the previous owners took it for service. I decided to try the Shell because I've used it in millions of dollars of equipment and trucks over the years without any issue. I've used mobil 1 in all my trucks since 2000. I just vary the weight in summer vs winter (WNY).