5W-30 , and it's best not to use the cheapest brand.
Supercharger oil for a 1993 Ford Thunderbird can be found at auto parts stores that sell racing performance parts. Usually, a 50 wt. oil will work for this type of engine.
I have been putting 10W30 Maxlife Valvoline in my 97 Ford Thunderbird. It is partially a synthetic oil that cuts down on wear and tear on your high mileage engine.
R-12 freon and 500 viscosity oil.........
My 1991 Mustang 5.0 LX came from the factory with ( 5W-30 ) I ASSUME your Ford Thunderbird would be the same
5W-30 is the preferred oil , according to the 1996 Ford Thunderbird Owner Guide
10w30. The brand is a personnal choice. I use Pennzoil.
Either at the rear or side of the oil pan.
10w30
What engine do you have?
SAE 10 W 30 Pennzoil 5 1/2 quarts spin on filter.
No, it has one oil drain plug.
Either at the rear or side of the oil pan