1984 Pontiac Phoenix Oil Type & Capacity

It depends on the engine: Base, 2D Coupe, 2.5 R, Automatic uses 5W-30; Base, 2D Coupe, 2.5 R, Standard, M19 uses 5W-30; Base, 2D Coupe, 2.5 R, Standard, MY8 uses 5W-30; Base, 2D Coupe, 2.8 X, Automatic uses 5W-30; Base, 2D Coupe, 2.8 X, Standard uses 5W-30; Base, 2D Coupe, 2.8 Z, Automatic uses 5W-30; Base, 2D Coupe, 2.8 Z, Standard uses 5W-30; Base, 4D Hatchback, 2.5 R, Automatic uses 5W-30; Base, 4D Hatchback, 2.5 R, Standard, M19 uses 5W-30; Base, 4D Hatchback, 2.5 R, Standard, MY8 uses 5W-30; Base, 4D Hatchback, 2.8 X, Automatic uses 5W-30; Base, 4D Hatchback, 2.8 X, Standard uses 5W-30; Base, 4D Hatchback, 2.8 Z, Automatic uses 5W-30; Base, 4D Hatchback, 2.8 Z, Standard uses 5W-30; LE, 2D Coupe, 2.5 R, Automatic uses 5W-30; LE, 2D Coupe, 2.5 R, Standard, M19 uses 5W-30; LE, 2D Coupe, 2.5 R, Standard, MY8 uses 5W-30; LE, 2D Coupe, 2.8 X, Automatic uses 5W-30; LE, 2D Coupe, 2.8 X, Standard uses 5W-30; LE, 2D Coupe, 2.8 Z, Automatic uses 5W-30; LE, 2D Coupe, 2.8 Z, Standard uses 5W-30; LE, 4D Hatchback, 2.5 R, Automatic uses 5W-30; LE, 4D Hatchback, 2.5 R, Standard, M19 uses 5W-30; LE, 4D Hatchback, 2.5 R, Standard, MY8 uses 5W-30; LE, 4D Hatchback, 2.8 X, Automatic uses 5W-30; LE, 4D Hatchback, 2.8 X, Standard uses 5W-30; LE, 4D Hatchback, 2.8 Z, Automatic uses 5W-30; LE, 4D Hatchback, 2.8 Z, Standard uses 5W-30; SE, Automatic uses 5W-30; SE, Standard uses 5W-30.

Capacity depends on the engine: Base, 2D Coupe, 2.5 R, Automatic holds 3.0 quarts with filter; Base, 2D Coupe, 2.5 R, Standard, M19 holds 3.0 quarts with filter; Base, 2D Coupe, 2.5 R, Standard, MY8 holds 3.0 quarts with filter; Base, 2D Coupe, 2.8 X, Automatic holds 4.0 quarts with filter; Base, 2D Coupe, 2.8 X, Standard holds 4.0 quarts with filter; Base, 2D Coupe, 2.8 Z, Automatic holds 4.0 quarts with filter; Base, 2D Coupe, 2.8 Z, Standard holds 4.0 quarts with filter; Base, 4D Hatchback, 2.5 R, Automatic holds 3.0 quarts with filter; Base, 4D Hatchback, 2.5 R, Standard, M19 holds 3.0 quarts with filter; Base, 4D Hatchback, 2.5 R, Standard, MY8 holds 3.0 quarts with filter; Base, 4D Hatchback, 2.8 X, Automatic holds 4.0 quarts with filter; Base, 4D Hatchback, 2.8 X, Standard holds 4.0 quarts with filter; Base, 4D Hatchback, 2.8 Z, Automatic holds 4.0 quarts with filter; Base, 4D Hatchback, 2.8 Z, Standard holds 4.0 quarts with filter; LE, 2D Coupe, 2.5 R, Automatic holds 3.0 quarts with filter; LE, 2D Coupe, 2.5 R, Standard, M19 holds 3.0 quarts with filter; LE, 2D Coupe, 2.5 R, Standard, MY8 holds 3.0 quarts with filter; LE, 2D Coupe, 2.8 X, Automatic holds 4.0 quarts with filter; LE, 2D Coupe, 2.8 X, Standard holds 4.0 quarts with filter; LE, 2D Coupe, 2.8 Z, Automatic holds 4.0 quarts with filter; LE, 2D Coupe, 2.8 Z, Standard holds 4.0 quarts with filter; LE, 4D Hatchback, 2.5 R, Automatic holds 3.0 quarts with filter; LE, 4D Hatchback, 2.5 R, Standard, M19 holds 3.0 quarts with filter; LE, 4D Hatchback, 2.5 R, Standard, MY8 holds 3.0 quarts with filter; LE, 4D Hatchback, 2.8 X, Automatic holds 4.0 quarts with filter; LE, 4D Hatchback, 2.8 X, Standard holds 4.0 quarts with filter; LE, 4D Hatchback, 2.8 Z, Automatic holds 4.0 quarts with filter; LE, 4D Hatchback, 2.8 Z, Standard holds 4.0 quarts with filter; SE, Automatic holds 4.0 quarts with filter; SE, Standard holds 4.0 quarts with filter.

Yes. 5W-30 is widely available as a full synthetic, and synthetic is safe (often recommended) for the 1984 Pontiac Phoenix. What matters most is matching the factory viscosity and specification, then changing the oil and filter on schedule.