You would as many quarts of oil as the same amount of cylinders you have If you have an 8 cylinder then you would need 8 quarts, if you have a 4 cylinder you would need 4 quarts of oil
8 quarts
2003 cad deville takes 4 quarts of motor oil
11
11
total of 16 quarts
5.5 quarts 5w-30w
12
It takes 5.5 Quarts with a fresh filter.
If it's the base Sedan Deville with the 4.9 liter, it's 5 quarts with the filter. For the Deville Concours with the Northstar, it's 7.5 quarts with the filter.
7.5, but you'll be good with 7.
According to my Cadillac dealer, the 98 DeVille holds 8 full quarts 7 1/2 quarts to the center of operating range only add 7 1/2 at oil and filter change!!
A 1990 Cadillac Deville air conditioner should hold 46 oz. R12 Freon. This should be verified through the owners vehicle manual.