What kind of oil does a 91 Chevy s10 blazer use?

A 1991 Chevy S10 Blazer's recommended oil type depends on the engine it has. You'll need to check your owner's manual for the exact specification. However, generally, these trucks used either:

* SAE 10W-30: This was a very common grade for these vehicles, particularly in moderate climates.

* SAE 5W-30: A slightly lighter weight oil, often preferred in colder climates.

Crucially: The owner's manual will also specify the oil type (conventional, synthetic blend, or fully synthetic) and the API certification (like SJ, SL, or SM - the letter designation will indicate the oil's quality and performance standards). Using the wrong type of oil can damage your engine.

To find the correct information:

1. Locate your owner's manual: This is the best source of information.

2. Check the oil fill cap: Sometimes, the recommended oil type is printed on the cap.

3. Look for a sticker under the hood: Many vehicles have a sticker detailing maintenance recommendations, including oil type.

Without knowing your specific engine size (e.g., 2.5L, 4.3L), it's impossible to give a definitive answer. Using the resources above will ensure you use the correct oil for your Blazer.