1991 GMC C3500 HD Oil Type & Capacity
The 1991 GMC C3500 HD oil type depends on the engine: the 5.7 K, Automatic takes 10W-30 (6.0 quarts qt with filter); the 5.7 K, Standard, NV4500/MT8 takes 10W-30 (6.0 quarts qt with filter); the 5.7 K, Standard, SM465/M20 takes 10W-30 (6.0 quarts qt with filter); the 6.2 J, Automatic takes 10W-30 (7.0 quarts qt with filter); the 6.2 J, Standard, NV4500/MT8 takes 10W-30 (7.0 quarts qt with filter); the 6.2 J, Standard, SM465/M20 takes 10W-30 (7.0 quarts qt with filter); the 7.4 N, Automatic takes 10W-30 (8.0 quarts qt with filter); the 7.4 N, Standard, NV4500/MT8 takes 10W-30 (8.0 quarts qt with filter); the 7.4 N, Standard, SM465/M20 takes 10W-30 (8.0 quarts qt with filter), per the factory service manual.
Factory-spec answer
It depends on the engine:
- 5.7 K, Automatic: 10W-30, 6.0 quarts with filter
- 5.7 K, Standard, NV4500/MT8: 10W-30, 6.0 quarts with filter
- 5.7 K, Standard, SM465/M20: 10W-30, 6.0 quarts with filter
- 6.2 J, Automatic: 10W-30, 7.0 quarts with filter
- 6.2 J, Standard, NV4500/MT8: 10W-30, 7.0 quarts with filter
- 6.2 J, Standard, SM465/M20: 10W-30, 7.0 quarts with filter
- 7.4 N, Automatic: 10W-30, 8.0 quarts with filter
- 7.4 N, Standard, NV4500/MT8: 10W-30, 8.0 quarts with filter
- 7.4 N, Standard, SM465/M20: 10W-30, 8.0 quarts with filter
Oil capacity by engine
| Engine | Oil Type (viscosity) | Capacity w/ Filter | Capacity w/o Filter | Notes |
|---|---|---|---|---|
| 5.7 K, Automatic — 5.7L Eng | API - SAE 10W-30 (Below 0Deg.F to 60Deg.F), 15W-40 (0Deg.F to Above 100Deg.F), SAE 30 (Above 32Deg.F to Above 100Deg.F) | 6.00 QTS. | 5.00 QTS. | — |
| 5.7 K, Standard, NV4500/MT8 — 5.7L Eng | API - SAE 10W-30 (Below 0Deg.F to 60Deg.F), 15W-40 (0Deg.F to Above 100Deg.F), SAE 30 (Above 32Deg.F to Above 100Deg.F) | 6.00 QTS. | 5.00 QTS. | — |
| 5.7 K, Standard, SM465/M20 — 5.7L Eng | API - SAE 10W-30 (Below 0Deg.F to 60Deg.F), 15W-40 (0Deg.F to Above 100Deg.F), SAE 30 (Above 32Deg.F to Above 100Deg.F) | 6.00 QTS. | 5.00 QTS. | — |
| 6.2 J, Automatic — 6.2L Eng | API - SAE 10W-30 (Below 0Deg.F to 60Deg.F), 15W-40 (0Deg.F to Above 100Deg.F), SAE 30 (Above 32Deg.F to Above 100Deg.F) | 7.00 QTS. | — | — |
| 6.2 J, Standard, NV4500/MT8 — 6.2L Eng | API - SAE 10W-30 (Below 0Deg.F to 60Deg.F), 15W-40 (0Deg.F to Above 100Deg.F), SAE 30 (Above 32Deg.F to Above 100Deg.F) | 7.00 QTS. | — | — |
| 6.2 J, Standard, SM465/M20 — 6.2L Eng | API - SAE 10W-30 (Below 0Deg.F to 60Deg.F), 15W-40 (0Deg.F to Above 100Deg.F), SAE 30 (Above 32Deg.F to Above 100Deg.F) | 7.00 QTS. | — | — |
| 7.4 N, Automatic — 7.4L Eng | API - SAE 10W-30 (Below 0Deg.F to 60Deg.F), 15W-40 (0Deg.F to Above 100Deg.F), SAE 30 (Above 32Deg.F to Above 100Deg.F) | 8.00 QTS. | 7.00 QTS. | — |
| 7.4 N, Standard, NV4500/MT8 — 7.4L Eng | API - SAE 10W-30 (Below 0Deg.F to 60Deg.F), 15W-40 (0Deg.F to Above 100Deg.F), SAE 30 (Above 32Deg.F to Above 100Deg.F) | 8.00 QTS. | 7.00 QTS. | — |
| 7.4 N, Standard, SM465/M20 — 7.4L Eng | API - SAE 10W-30 (Below 0Deg.F to 60Deg.F), 15W-40 (0Deg.F to Above 100Deg.F), SAE 30 (Above 32Deg.F to Above 100Deg.F) | 8.00 QTS. | 7.00 QTS. | — |
More factory specs & repair guides for your C3500 HD
🛞 1991 GMC C3500 HD Tire Size & Pressure →🌧️ 1991 GMC C3500 HD Wiper Blade Sizes →💡 1991 GMC C3500 HD Light Bulb Sizes →📖 1991 GMC C3500 HD Factory Service Manual →All fluid capacities (transmission, coolant, brakes)Powered by factory manual data from our partner network AllOEMManuals.com.
Coolant capacity
27.0 quarts (25.55 L) — 56/44 mixture of Ethylene Glycol Base Antifreeze and water. GM Specification 1825-M.
Frequently asked questions
What type of oil does a 1991 GMC C3500 HD take?
It depends on the engine: 5.7 K, Automatic uses 10W-30; 5.7 K, Standard, NV4500/MT8 uses 10W-30; 5.7 K, Standard, SM465/M20 uses 10W-30; 6.2 J, Automatic uses 10W-30; 6.2 J, Standard, NV4500/MT8 uses 10W-30; 6.2 J, Standard, SM465/M20 uses 10W-30; 7.4 N, Automatic uses 10W-30; 7.4 N, Standard, NV4500/MT8 uses 10W-30; 7.4 N, Standard, SM465/M20 uses 10W-30.
What is the oil capacity of a 1991 GMC C3500 HD?
Oil capacity depends on the engine: 5.7 K, Automatic holds 6.0 quarts with filter; 5.7 K, Standard, NV4500/MT8 holds 6.0 quarts with filter; 5.7 K, Standard, SM465/M20 holds 6.0 quarts with filter; 6.2 J, Automatic holds 7.0 quarts with filter; 6.2 J, Standard, NV4500/MT8 holds 7.0 quarts with filter; 6.2 J, Standard, SM465/M20 holds 7.0 quarts with filter; 7.4 N, Automatic holds 8.0 quarts with filter; 7.4 N, Standard, NV4500/MT8 holds 8.0 quarts with filter; 7.4 N, Standard, SM465/M20 holds 8.0 quarts with filter.
How often should I change the oil in my 1991 GMC C3500 HD?
Most 1991 GMC C3500 HD 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 — GMC recommends intervals based on driving conditions, not just mileage.
Can I use synthetic oil in my 1991 GMC C3500 HD?
Yes. 10W-30 is widely available as a full synthetic, and synthetic is safe (often recommended) for the 1991 GMC C3500 HD. What matters most is matching the factory viscosity and specification, then changing the oil and filter on schedule.