2005 Cadillac STS Oil Type & Capacity
The 2005 Cadillac STS oil type depends on the engine: the 3.6 7 takes 5W-30 (6.0 quarts qt with filter); the 4.6 A, AWD takes 5W-30 (8.0 quarts qt with filter); the 4.6 A, RWD takes 5W-30 (8.0 quarts qt with filter), per the factory service manual.
Factory-spec answer
It depends on the engine:
- 3.6 7: 5W-30, 6.0 quarts with filter
- 4.6 A, AWD: 5W-30, 8.0 quarts with filter
- 4.6 A, RWD: 5W-30, 8.0 quarts with filter
Oil capacity by engine
| Engine | Oil Type (viscosity) | Capacity w/ Filter | Capacity w/o Filter | Notes |
|---|---|---|---|---|
| 3.6 7 — 3.6L Eng | API - SAE 5W-30 | 6.00 QTS. | — | Use synthetic oil that meets GM Standard GM4718M. DO NOT use other viscosity oils such as SAE 20W-50. |
| 4.6 A, AWD — 4.6L Eng | API - SAE 5W-30 | 8.00 QTS. | — | Use synthetic oil that meets GM Standard GM4718M. DO NOT use other viscosity oils such as SAE 20W-50. |
| 4.6 A, RWD — 4.6L Eng | API - SAE 5W-30 | 8.00 QTS. | — | Use synthetic oil that meets GM Standard GM4718M. DO NOT use other viscosity oils such as SAE 20W-50. |
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More factory specs & repair guides for your STS
🛞 2005 Cadillac STS Tire Size & Pressure →🌧️ 2005 Cadillac STS Wiper Blade Sizes →💡 2005 Cadillac STS Light Bulb Sizes →📖 2005 Cadillac STS Factory Service Manual →All fluid capacities (transmission, coolant, brakes)Powered by factory manual data from our partner network AllOEMManuals.com.
Coolant capacity
13.0 quarts (12.3 L) — 50/50 mixture of DEX-COOL and clean drinkable water
Frequently asked questions
What type of oil does a 2005 Cadillac STS take?
It depends on the engine: 3.6 7 uses 5W-30; 4.6 A, AWD uses 5W-30; 4.6 A, RWD uses 5W-30.
What is the oil capacity of a 2005 Cadillac STS?
Oil capacity depends on the engine: 3.6 7 holds 6.0 quarts with filter; 4.6 A, AWD holds 8.0 quarts with filter; 4.6 A, RWD holds 8.0 quarts with filter.
How often should I change the oil in my 2005 Cadillac STS?
Most 2005 Cadillac STS 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 — Cadillac recommends intervals based on driving conditions, not just mileage.
Can I use synthetic oil in my 2005 Cadillac STS?
Yes. 5W-30 is widely available as a full synthetic, and synthetic is safe (often recommended) for the 2005 Cadillac STS. What matters most is matching the factory viscosity and specification, then changing the oil and filter on schedule.