2003 Buick Regal Oil Type & Capacity: 10W-30 (4.5 quarts)
The 2003 Buick Regal takes 10W-30 motor oil — 4.5 quarts with a filter change, per the factory service manual.
Factory-spec answer
10W-30 — 4.5 quarts with filter
Oil capacity by engine
| Engine | Oil Type (viscosity) | Capacity w/ Filter | Capacity w/o Filter | Notes |
|---|---|---|---|---|
| GS | API - SAE 10W-30 | 4.50 QTS. | — | — |
| LS | API - SAE 10W-30 | 4.50 QTS. | — | — |
More factory specs & repair guides for your Regal
🛞 2003 Buick Regal Tire Size & Pressure →🌧️ 2003 Buick Regal Wiper Blade Sizes →💡 2003 Buick Regal Light Bulb Sizes →📖 2003 Buick Regal Factory Service Manual →All fluid capacities (transmission, coolant, brakes)Powered by factory manual data from our partner network AllOEMManuals.com.
Coolant capacity
11.7 quarts (11.07 L) — 50/50 mixture of DEX-COOL and clean drinkable water
Frequently asked questions
What type of oil does a 2003 Buick Regal take?
The 2003 Buick Regal takes 10W-30 motor oil (API - SAE 10W-30), per the factory service manual.
What is the oil capacity of a 2003 Buick Regal?
The 2003 Buick Regal oil capacity is 4.5 quarts with a filter change.
How often should I change the oil in my 2003 Buick Regal?
Most 2003 Buick Regal owners follow a 5,000–7,500 mile interval with conventional oil, or up to 10,000 miles with full synthetic. Always check the oil life monitor if equipped, and consult your owner's manual — Buick recommends intervals based on driving conditions, not just mileage.
Can I use synthetic oil in my 2003 Buick Regal?
Yes. 10W-30 is widely available as a full synthetic, and synthetic is safe (often recommended) for the 2003 Buick Regal. What matters most is matching the factory viscosity and specification, then changing the oil and filter on schedule.