Which specification does Axle & differential oil need for the Porsche 911 Turbo (1974–1978)?

Axle & differential oil for the Porsche 911 Turbo (1974–1978): 85W-90, API GL4, API GL5.

Which specification does Brake fluid need for the Porsche 911 Turbo (1974–1978)?

Brake fluid for the Porsche 911 Turbo (1974–1978): DOT 3, FMVSS 116 DOT 3.

Suitable for Porsche 911 Turbo (1974–1978)

For the Porsche 911 Turbo (1974–1978), the manufacturer specifies motor oil 10W-40 (ACEA A3, ACEA B4, API SL), 10W-60 (ACEA A3, ACEA B4, API SN), 20W-20 (API SJ), or 20W-50 (ACEA A3, ACEA B4, API SC).

Fluids and approvals for the Porsche 911 Turbo (1974–1978)

Fluid	Requirement
Motor oil	10W-40: ACEA A3, ACEA B4, API SL10W-60: ACEA A3, ACEA B4, API SN20W-20: API SJ20W-50: ACEA A3, ACEA B4, API SC
Axle & differential oil	85W-90, API GL4, API GL5
Brake fluid	DOT 3, FMVSS 116 DOT 3