1986 Buick Somerset Oil Type & Capacity
The 1986 Buick Somerset oil type depends on the engine: the Custom, 2.5 U takes 5W-30 (3.0 quarts with filter); the Custom, 3.0 L takes 5W-30 (4.0 quarts with filter); the Limited, 2.5 U takes 5W-30 (3.0 quarts with filter); the Limited, 3.0 L takes 5W-30 (4.0 quarts with filter); the T-Type takes 5W-30 (4.0 quarts with filter), per the factory service manual.
Factory-spec answer
It depends on the engine:
- Custom, 2.5 U: 5W-30, 3.0 quarts with filter
- Custom, 3.0 L: 5W-30, 4.0 quarts with filter
- Limited, 2.5 U: 5W-30, 3.0 quarts with filter
- Limited, 3.0 L: 5W-30, 4.0 quarts with filter
- T-Type: 5W-30, 4.0 quarts with filter
Oil capacity by engine
| Engine | Oil Type (viscosity) | Capacity w/ Filter | Capacity w/o Filter | Notes |
|---|---|---|---|---|
| Custom, 2.5 U — 2.5L Eng | SAE 5W-30 (Preferred) (Below -20Deg.F to Above 100Deg.F), 10W-30 (0Deg.F to Above 100Deg.F) | 3.00 QTS. | — | — |
| Custom, 3.0 L — 3.0L Eng | SAE 5W-30 (Preferred) (Below -20Deg.F to Above 100Deg.F), 10W-30 (0Deg.F to Above 100Deg.F) | 4.00 QTS. | — | — |
| Limited, 2.5 U — 2.5L Eng | SAE 5W-30 (Preferred) (Below -20Deg.F to Above 100Deg.F), 10W-30 (0Deg.F to Above 100Deg.F) | 3.00 QTS. | — | — |
| Limited, 3.0 L — 3.0L Eng | SAE 5W-30 (Preferred) (Below -20Deg.F to Above 100Deg.F), 10W-30 (0Deg.F to Above 100Deg.F) | 4.00 QTS. | — | — |
| T-Type — 3.0L Eng | SAE 5W-30 (Preferred) (Below -20Deg.F to Above 100Deg.F), 10W-30 (0Deg.F to Above 100Deg.F) | 4.00 QTS. | — | — |
Buy the right oil
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More specs & repair guides for your Somerset
1986 Buick Somerset factory service manualAll fluid capacities (transmission, coolant, brakes)Powered by factory manual data from our partner site AllOEMManuals.com.
Coolant capacity
8.0 quarts (7.57 L) — 50/50 mixture of Ethylene Glycol Base Antifreeze and water. GM Specification 1825-M.
Frequently asked questions
What type of oil does a 1986 Buick Somerset take?
It depends on the engine: Custom, 2.5 U uses 5W-30; Custom, 3.0 L uses 5W-30; Limited, 2.5 U uses 5W-30; Limited, 3.0 L uses 5W-30; T-Type uses 5W-30.
How much oil does a 1986 Buick Somerset take?
Capacity depends on the engine: Custom, 2.5 U holds 3.0 quarts with filter; Custom, 3.0 L holds 4.0 quarts with filter; Limited, 2.5 U holds 3.0 quarts with filter; Limited, 3.0 L holds 4.0 quarts with filter; T-Type holds 4.0 quarts with filter.
Can I use synthetic oil in my 1986 Buick Somerset?
Yes. 5W-30 is widely available as a full synthetic, and synthetic is safe (often recommended) for the 1986 Buick Somerset. What matters most is matching the factory viscosity and specification, then changing the oil and filter on schedule.