1991 Isuzu Impulse Oil Type & Capacity: 5W-20 (4.6 quarts)
The 1991 Isuzu Impulse takes 5W-20 motor oil — 4.6 quarts with a filter change, per the factory service manual.
Factory-spec answer
5W-20 — 4.6 quarts with filter
Oil capacity by engine
| Engine | Oil Type (viscosity) | Capacity w/ Filter | Capacity w/o Filter | Notes |
|---|---|---|---|---|
| RS | API - SAE 5W-20 (Below 60Deg.F), 10W-30 (Above 0Deg.F), 30 (Above 40Deg.F), 15W-40, 20W-40/50 (Above 10Deg.F) | 4.60 QTS. | 4.00 QTS. | — |
| XS, 2D Coupe, Automatic | API - SAE 5W-20 (Below 60Deg.F), 10W-30 (Above 0Deg.F), 30 (Above 40Deg.F), 15W-40, 20W-40/50 (Above 10Deg.F) | 4.60 QTS. | 4.00 QTS. | — |
| XS, 2D Coupe, Standard | API - SAE 5W-20 (Below 60Deg.F), 10W-30 (Above 0Deg.F), 30 (Above 40Deg.F), 15W-40, 20W-40/50 (Above 10Deg.F) | 4.60 QTS. | 4.00 QTS. | — |
| XS, 2D Hatchback, Automatic | API - SAE 5W-20 (Below 60Deg.F), 10W-30 (Above 0Deg.F), 30 (Above 40Deg.F), 15W-40, 20W-40/50 (Above 10Deg.F) | 4.60 QTS. | 4.00 QTS. | — |
| XS, 2D Hatchback, Standard | API - SAE 5W-20 (Below 60Deg.F), 10W-30 (Above 0Deg.F), 30 (Above 40Deg.F), 15W-40, 20W-40/50 (Above 10Deg.F) | 4.60 QTS. | 4.00 QTS. | — |
Complete Oil Change Bundle for 1991 Isuzu Impulse
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More factory specs & repair guides for your Impulse
🛞 1991 Isuzu Impulse Tire Size & Pressure →🌧️ 1991 Isuzu Impulse Wiper Blade Sizes →💡 1991 Isuzu Impulse Light Bulb Sizes →📖 1991 Isuzu Impulse Factory Service Manual →All fluid capacities (transmission, coolant, brakes)Powered by factory manual data from our partner network AllOEMManuals.com.
Coolant capacity
7.3 quarts (6.9 L) — 50/50 mixture of Ethylene Glycol Antifreeze and water
Frequently asked questions
What type of oil does a 1991 Isuzu Impulse take?
The 1991 Isuzu Impulse takes 5W-20 motor oil (API - SAE 5W-20 (Below 60Deg.F), 10W-30 (Above 0Deg.F), 30 (Above 40Deg.F), 15W-40, 20W-40/50 (Above 10Deg.F)), per the factory service manual.
What is the oil capacity of a 1991 Isuzu Impulse?
The 1991 Isuzu Impulse oil capacity is 4.6 quarts with a filter change, or 4.0 quarts without changing the filter.
How often should I change the oil in my 1991 Isuzu Impulse?
Most 1991 Isuzu Impulse 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 — Isuzu recommends intervals based on driving conditions, not just mileage.
Can I use synthetic oil in my 1991 Isuzu Impulse?
Yes. 5W-20 is widely available as a full synthetic, and synthetic is safe (often recommended) for the 1991 Isuzu Impulse. What matters most is matching the factory viscosity and specification, then changing the oil and filter on schedule.