1991 Buick Roadmaster Oil Type & Capacity
The 1991 Buick Roadmaster takes 5W-30 motor oil — 4.0 quarts with a filter change, per the factory service manual.
Factory-spec answer
5W-30 — 4.0 quarts with filter
Oil capacity by engine
| Engine | Oil Type (viscosity) | Capacity w/ Filter | Capacity w/o Filter | Notes |
|---|---|---|---|---|
| 4L60/MD8 — 5.0L Eng | API - SAE 5W-30 (Below -20Deg.F to 60Deg.F), 10W-30 (Preferred) (0Deg.F to Above 100Deg.F) | 4.00 QTS. | — | — |
| 700R4/MD8 — 5.0L Eng | API - SAE 5W-30 (Below -20Deg.F to 60Deg.F), 10W-30 (Preferred) (0Deg.F to Above 100Deg.F) | 4.00 QTS. | — | — |
Buy the right oil
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More specs & repair guides for your Roadmaster
1991 Buick Roadmaster factory service manualAll fluid capacities (transmission, coolant, brakes)Powered by factory manual data from our partner site AllOEMManuals.com.
Coolant capacity
17.5 quarts (16.56 L) — 50/50 mixture of Ethylene Glycol Base Antifreeze and water. GM Specification 1825-M.
Frequently asked questions
What type of oil does a 1991 Buick Roadmaster take?
The 1991 Buick Roadmaster takes 5W-30 motor oil (API - SAE 5W-30 (Below -20Deg.F to 60Deg.F), 10W-30 (Preferred) (0Deg.F to Above 100Deg.F)), per the factory service manual.
How much oil does a 1991 Buick Roadmaster take?
The 1991 Buick Roadmaster holds 4.0 quarts with a filter change.
Can I use synthetic oil in my 1991 Buick Roadmaster?
Yes. 5W-30 is widely available as a full synthetic, and synthetic is safe (often recommended) for the 1991 Buick Roadmaster. What matters most is matching the factory viscosity and specification, then changing the oil and filter on schedule.